The post The Complete Guide to Mild Steel Grades and Their Uses appeared first on Rapid Metals.

The post Should You Use Galvanised or Non Galvanised Steel for Your Project? appeared first on Rapid Metals.

Rapid Metals is your leading supplier of aluminium sheet metal for all these applications and more. We make getting the aluminium sheet you need simple, with our powerful online store, quick nationwide delivery and dedication to customer service.

One of the many elements you can set in the Rapid Metals online store is the aluminium sheet thickness. You can specify the length and width to your exact bespoke requirements (down to the millimetre!), but, like all metal suppliers, we sell our aluminium sheet in a range of standard thicknesses.

Why is this? And which aluminium sheet thickness should you choose for your project? We will answer these questions in this blog.

ALUMINIUM SHEET FROM RAPID METALS

All of Rapid Metals’ aluminium sheet is 1050 grade aluminium. This is a ‘commercially pure’ aluminium product, composed of 99.5% aluminium and minimal amounts of other elements.

Our aluminium sheet starts life as large ingots of aluminium, perhaps weighing many tons each. These are heated and passed through a rolling mill to produce large, flat billets. Stretching and straightening in this way relieves internal stresses and work-hardens the metal, giving it greater strength and much more consistent structure and finish. The billet of aluminium is heated again and put through a finer continuous mill to flatten further and thin it. This is then coiled into a roll of thick sheet or plate, for storage or transport.

The final sheet is produced by unrolling this metal and passing it through a further, finer set of rollers when cold. Cold-rolling produces more consistent and precise dimensions than hot rolling, allowing the aluminium sheet thickness to be finely adjusted and controlled, right down to 0.5mm thick aluminium sheet in some cases. Aluminium foil can be rolled (often with pairs of sheets) down to just 0.015mm, or even less for specialist materials.

This is why metal suppliers can only offer certain aluminium sheet thicknesses – they are produced by the manufacturer, and aluminium sheets are made in large quantities on rollers set to specific thicknesses.

If the thickness of the piece is greater than 6mm, the product is considered to be aluminium plate rather than aluminium sheet

While it’s practical to cut aluminium sheet to bespoke lengths and widths, it isn’t practical to cut or grind large sheets to specific thicknesses. It’s also very unusual to find applications where the aluminium sheet thickness is vital enough that it has to be made bespoke, while there is great benefit to specifying the other dimensions exactly, from creating panels that fit a particular space to minimising wastage.

However, you do still need to know which standard aluminium sheet thickness is the most suitable for your project – foil-thin aluminium sheet and thick structural sheet are not interchangeable!

ALUMINIUM SHEET THICKNESSES

One of aluminium’s primary characteristics is its good strength-to-weight ratio. But the ultimate strength of a sheet of aluminium depends to a great extent on its thickness. The aluminium sheet thickness will also largely determine the durability, flexibility and weight of the sheet.

The thinnest standard aluminium sheet thickness that Rapid Metals supplies is 1mm. As a thin sheet, this is easily bent, folded and formed into shapes, as well as having good malleability and ductility. It can be made into strong load-bearing forms to compensate for its relative lack of inherent strength.

1MM ALUMINIUM SHEET THICKNESS

1mm aluminium sheet is used for making packs and containers where hygiene and security are important, such as the food and pharmaceutical industries. Vehicle body structures and panels can also be made from 1mm aluminium sheet. So can parts of electronic items, whether that is the external case or internal parts like armatures or heat sinks. This thickness of aluminium sheet can also be used to make engraved signs or placards.

1.2MM AND 1.5MM ALUMINIUM SHEET THICKNESS

If you need the formability and minimal weight of 1mm aluminium sheet but need more of a margin for strength or durability, 1.2mm and 1.5mm aluminium sheet thicknesses can be a suitable choice. Aluminium sheet of 1.2mm or 1.5mm is a common choice for making kitchen cabinets, drawers and cupboards, with a good balance of light weight, low cost and durability. Many prefab buildings such as workshops, industrial units and utility sheds, use aluminium panels of 1.2mm or 1.5mm thickness as the curtain walls between load-bearing beams.

2MM ALUMINIUM SHEET THICKNESS

2mm aluminium sheet boasts better strength, durability and fatigue resistance while still having good formability characteristics. The greater mass of the sheet can also be a benefit when you are making use of aluminium’s heat transferring properties, such as making heat sinks, sockets, mounts and armatures for electronic components. It can also be used for making enclosures, battery trays and non-structural architectural parts such as cladding and sunshades.

3MM ALUMINIUM SHEET THICKNESS

A 3mm aluminium sheet thickness brings a great deal of versatility, with a very useful blend of strength and formability. This thickness is the minimum legally permitted for pressure vessels made of aluminium. The extra thickness gives products made from 3mm aluminium sheet greater resistance to flexing, bending and fatigue, and can bear moderate or intermittent loads. Liquid tanks, such as industrial storage tanks or the outer cases of vehicle fuel tanks, are often made of 3mm aluminium. 3mm aluminium sheet is also a recommended minimum for making floors, so long as the sheet itself is well supported. It can be especially useful where weight has to be minimised, but you want a corrosion-resistant material, such as in boats, trailers, caravans and horse boxes.

This is also a common thickness for kitchen work surfaces and splashbacks, combining durability with a hygienic and easily-cleaned finish. Staying in the kitchen, 3mm is also the minimum recommended thickness for the base of cookware made of aluminium, since this presents enough mass to evenly distribute the heat.

4MM ALUMINIUM SHEET THICKNESS

This is the thickness found in the base of heavy-duty kitchenware intended for professional use. You’ll also find this thickness of aluminium sheet used to make interior fittings such as handrails, kick plates and door handles that must be strong and resilient. It can also be used as cladding for buildings, and is strong and resilient enough to be used as a roofing material.

5MM AND 6MM ALUMINIUM SHEET THICKNESS

Very thick aluminium sheet (which may be available as large as 10mm thick aluminium sheet) is mainly used for forming structural load-bearing parts, or specialist applications like heavy-duty pressure vessels.

CHOOSING ALUMINIUM SHEET THICKNESS – A SUMMARY

There simply isn’t room to list all the potential applications for aluminium sheets of different thicknesses. When selecting metal for your project, bear the following guidance in mind:

• Up to 1.5mm:Lightweight and easily formable. For precision, crafting and non-structural or load-bearing functions.
• 1.5mm to3mm: Medium-duty, a good combination of low weight, formability and durability. Can bear moderate loads.
• Above 3mm: Heavy taskswhere durability and strengths trump formability. Good for structural or protective purposes.

Whatever you need aluminium sheet for, contact Rapid Metals. We can advise you on the right grade and thickness of aluminium sheet for your project. If you require a specific type of metal, we can work with our suppliers to source it. No order is too difficult, too large or too small!

The post WHICH ALUMINIUM SHEET THICKNESS SHOULD YOU CHOOSE FOR YOUR PROJECT? appeared first on Rapid Metals.

Today, two of the most common tool steels used in industries around the world are graded as A2 and D2. What do we mean when we talk about A2 steel vs D2 steel? What are the properties of D2 vs A2 steel, and what uses are these important metals put to?

Rapid Metals includes tool steels in our wide range of metals and metal products. As one of the UK’s foremost metal suppliers, we can answer these questions about A2 steel vs D2 steel. Read – and enjoy – our blog to learn more.

Grading Tool Steel

The terms A2 Steel and D2 steel both refer to the standardised way of grading and describing tool steels. The system was developed by the American Iron and Steel Institute (AISI) and the Society of Automotive Engineers (SAE), and groups tool steels based on the characteristics of their material and their basic applications.

There are six common categories of tool steel under the AISI/SAE system, each represented by a letter: water-hardening (W), oil-hardening (O), air-hardening (A), high carbon-chromium (D), shock-resisting (S) and hot-working (H). There are other specialist types such as high-speed (T and M), low-alloy (L) and carbon tungsten (F).

So already we can see that when we’re looking at A2 steel vs D2 steel we’re comparing an air-hardening tool steel and a high carbon-chromium type. They are notably different in terms of their composition as well – D2 has slightly more carbon and more than double the chromium content as A2.

With different classifications, they’re certain to have different characteristics and uses.

Within each group, the number refers to a specific variety of tool steel of that broad type – while there are different varieties of air-hardened tool steels, all their classifications will start with ‘A’, for instance.

The Difference Between A2 Steel vs D2 Steel

So if A2 tool steel and D2 tool steel are different enough to be given different classifications, what does this mean in the real world?

Fundamentally, all the metallurgical, chemical and physical differences of A2 steel vs D2 steel come down to this: A2 offers greater toughness but reduced hardness when compared to D2 tool steel.

In everyday speech, toughness and hardness are virtually synonyms, but they have very specific and vitally different meanings when discussing the property of materials.

Toughness is the material’s ability to absorb energy, deform and be shaped without breaking. Hardness is the material’s ability to withstand localised surface forces that cause indentation, scratching and surface wear.

For example, pure copper has high toughness but low hardness – it can be rolled, folded, shaped and drawn without breaking, but is easily scratched and wears quickly. A ceramic plate is the opposite – it resists scratching and wear very well but is brittle and will break under impact or high force.

When considered across the whole range of available materials (or even all the different types of metal) all tool steels have high hardness because this is what gives them their ability to retain a sharp, precise cutting edge for tool work.

But within the world of tool steels, and considering A2 steel vs D2 steel, A2 steel is tougher but softer than D2 steel.

The Properties of A2 vs D2 Tool Steel

The different alloy compositions and treatments that give A2 and D2 tool steel their respective hardness and toughness also give them differing properties in other ways:

1) Machineability: With lower hardness but higher toughness, A2 tool steel has better machining properties, being more easily cut to precise and complex shapes and resisting cracking and impact damage when being worked.

2) Wear Resistance: D2 tool steel’s superior hardness gives it better resistance to abrasive wear and means that it retains edges and profiles extremely well.

3) Temperature Resistance: D2 tool steel has slightly better performance in high temperatures, retaining its specified hardness up to around 480 deg. C (900 deg. F), while A2 tool steel begins to soften at around 425 deg. C (800 deg. F).

The Uses of A2 vs D2 Tool Steel

With higher toughness and better machineability, but less wear and abrasion resistance, A2 tool steel is suitable for many tooling applications where high speeds or heavy cutting actions are not required.

These uses typically include dies for stamping, forming, trimming and punching. A2 tool steel is also used for blanking tools and shear blades. It can be a good choice for making measuring gauges (tools for determining clearances and sizes rather than instruments), as these functions need accuracy and precision but do not impose a lot of impact or abrasive stress.

By contrast, with superior hardness giving excellent wear resistance and good temperature control, D2 tool steel is ideal for cutting tools such as punches, saw blades and drill bits. It can also be used for making extrusion tooling, forging tools and various types of plastic mould. The hard-wearing properties and good dimensional stability of D2 tool steel also means that its uses can go beyond tools themselves, and it can also be used in the making of mechanical components such as gears, bearings and shafts.

D2 Tool Steel from Rapid Metals

With D2 tool steel being one of the most versatile grades of tool steel, it should be no surprise that Rapid Metals includes it in our range of tool steels. We can supply D2 tool steel as round bar, in a range of popular metric or Imperial diameters and cut to the length you require. We can also supply D2 tool steel as steel block, which you can order to any length, width and height as needed.

Although A2 tool steel isn’t part of our standard range in our online store, if you need it please do contact our team. We can work with our network of suppliers and provide a quote – we aim to please, whatever the size or scope of the order.

The post A2 Steel vs D2 Steel: Key Differences and Best Uses appeared first on Rapid Metals.

As all of the different tool steel grades offer something unique and are made for various applications, you need to understand the difference between each and know what they can be used for. Our guide helps you to wrap your head around the different grades of tool steel so that you can make sure that you choose the right one for your project. Explore this material’s properties, differences, applications and grades to help you find the perfect solution for every task.

What is Tool Steel Material?

Before you can understand the different grades, you need to know what tool steel material actually is. This is basically a metal that’s designed for making a range of different tools to suit your needs, allowing you to precisely machine and engineer various products. The metal is made from a group of carbon and alloy steels to make it tough and resistant to wear, so you can cut, shape, stamp or form other materials once made into a tool. It can maintain hardness under stress and constant heavy-duty applications, withstanding high temperatures to offer you a reliable tool that can last for years to come.

Tool steel is different from standard structural steels because it’s made up of a combination of alloying elements, like tungsten, chromium, molybdenum, vanadium and cobalt. Having these elements improves the steel’s hardness, toughness and ability to withstand abrasion.

The Properties of Tool Steel

Tool steel has many unique properties that make it ideal for harsh conditions and demanding applications. The main properties of this material are:

• Exceptional hardness to allow tools to keep their cutting edges sharp.
• Impressive heat resistance to maintain strength at very high temperatures.
• Great wear resistance to make tools last for longer, preventing breakage and wear.
• Improved dimensional stability to always give you precision in multiple applications.
• Unmatched toughness and strength to prevent cracking and breakage during constant heavy-duty use.

What Are the Uses of Tool Steel?

The uses of tool steel can be highly varied because it can create a wide range of tools for an array of applications. It can make punches, dies, shear blades, industrial knives and precision tooling to suit your needs and individual project. This means that the material can easily make other products using a multitude of materials, such as metals, plastics and woods. They typically come in a softer condition that is machined into the tools you need before it’s heat-treated to improve the hardness.

Types of Tool Steel Material

Tool steel material comes in different types, which all have different grades. This means that there are specific tool steels for particular applications. Each type can make different tools that provide unique properties to suit your project needs, and every task within it. It’s important to know the different types of tool steel to make sure that you get the right one for the job, allowing you to make high-quality tools that last and offer unparalleled precision.

High Speed Tool Steel

This type of tool steel material is designed to create tools for machines that need to work at high speeds and temperatures. It can also be used for producing a variety of cutting tools that have to work at high speeds and hot temperatures. This steel can withstand heavy, constant use and retain a sharp cutting edge and its hardness at very high temperatures. It can do this due to the high amounts of tungsten, molybdenum and vanadium that it’s made from.

Shock-Resisting Tool Steel

Shock-resistant tool steel is crafted to absorb and take on harsh impacts and jolts, without breaking, shattering or fracturing. These tool steels usually have chromium and nickel in them to further improve their toughness and impact resistance.

Cold-Working Tool Steel

This type of tool steel material is typically hardened in oil or air to give you unparalleled wear resistance and almighty strength when used at low temperatures. It’s made for tools that are used in colder temperatures to provide a precise, flawless finish. It contains alloying elements to offer exceptional durability, toughness and resistance to wear.

These can come in different grades, such as O-series, A-series and D-series. The O-series is great for moderate wear applications, while the A-series is ideal for any tasks that have constant, heavy-duty use because it has an impressive wear resistance and high stability. As for the D-series, this is the best for die-casting and stamping dies due to its hardness.

Hot-Working Tool Steel

Hot-working tool steel is designed to maintain impressive hardness when used on projects that need high temperatures. This type of material boasts an extraordinary resistance to heat deformation, allowing you to have a quality, sharp tool under extreme heat without it bending, snapping or breaking. On top of this, the steel can be hardened by air or oil to create the exact tool you need for the job, depending on the grade.

Water-Hardening Tool Steel

As for water-hardening tool steel, this undergoes a hardening process by putting it in water. This gives the steel a moderate hardness, but it does have less resistance to wear, heat and corrosion compared to other types of tool steel material. However, this type of tool steel is very cost-effective, allowing you to create quality tools without the high cost.

The Different Grades of Tool Steel

Many of the types of tools steel can come in different grades, each of which offers something unique. The grades of tool steel impact the outcome you want when creating quality tools for specific purposes. This means that it’s important to choose the right grade for your project, so that you can have the best tools for the job.

O1

O1 tool steel grade stands for oil-hardening, which means the grade is for any hot-working tool steel that’s been hardened in oil. This is a popular grade for many because it’s very adaptable. It can be used for a variety of tools and applications, while offering unmatched quality. This grade has a winning combination of hardness and toughness, as well as impressive machinability, making it an ideal choice for heavy-duty use. It’s typically used for tools that need to have a medium level of abrasion resistance.

D2

D2 is typically the tool steel grade for cold-working steel. This is known for its excellent wear resistance because it has a high carbon and chromium content. D2 tool steel is very hard and brittle with a high abrasion resistance, which makes it ideal for cutting tools.

H13

This grade of tool steel is usually for hot-working steel. It has a great resistance to heat, allowing the tool to be used at high temperatures, as well as impressive thermal fatigue. This material can keep its hardness and toughness in high heat to make tools that need to carry out hot-working applications.

S7

S7 is the grade for shock-resistant tool steel. This is typically air-hardened to provide high toughness and impact resistance. S7 is a great material for making tools that need to withstand a lot of mechanical shock.

A2

The A2 tool steel grade is the grade for air-hardening steel. This gives you a wonderful balance of toughness and wear resistance, which helps it to minimise deformation during heat treatment. A2 is particularly useful for creating intricate tools.

M2/ M42

M2 and M42 grades are both for high-speed tool steel materials. M2 can keep impressive hardness and resistance to wear when working at speed and even higher temperatures. It can also maintain a sharp cutting edge to give you the best performance possible for a longer time. M42 is a cobalt-alloyed tool steel that offers unmatched wear resistance and toughness, particularly at high cutting speeds. It can also withstand high temperatures.

W1

This type of tool steel grade is typically the water-hardening tool steel type, which is easy to harden and used for general-purpose tools. W1 is made with a huge amount of carbon to improve its hardness. However, this grade is more fragile than others.

The Hardness Grades of Tool Steel

The grades of tool steel each have their own level of hardness, which is important to know to be able to choose the right one for your project. Understanding the hardness grades of tool steel shows you which tool steel can be used for heavy-duty applications and which are best for tools that need to carry out more precise, fragile work.

• H13 has the lowest hardness of 50-55.
• W1 has a hardness of 55-64.
• A2 has a hardness of 57-62.
• O1 has a hardness of 58-64.
• D2 has a hardness of 58-62.
• M2 has a hardness of 62-65.
• M42 has the highest hardness of 64-66.

Tool Steel Uses for Each Grade

Each grade of tool steel has its own unique uses. This is vital to know for you to choose the right steel for the job. The tool steel uses of these grades help determine which type you can use for the type of tools you want to create.

O1

The uses of tool steels that are in the grade O1 are very versatile. However, this grade is best to use for cutting tools, punches, shear blades and dies.

D2

D2 tool steel is best used for tools that need to face constant use, which means they need to provide high-wear resistance. It’s good for blanking punches, cutting tools and dies.

H13

This type of tool steel is best for tools that need to be used at high temperatures. It’s ideal for dies for forging, plastic moulds and extrusion dies.

S7

The tool steel uses of S7 are any application that creates a high shock impact. This means that it can be used for cold chisels, riveting tools, jackhammer bits and pneumatic tools.

A2

A2 is typically used for tools that need to have a balance of toughness and wear resistance, such as dies and punches.

M2/ M42

M2 uses are usually for high-speed cutting tools. This means that it’s great to make drills, milling cutters, reamers and taps. As for the uses of tool steel in M42, this is best used for high-performance cutting tools. This includes milling cutters, saw blades and drills.

W1

W1 tool steel material is a grade that’s made for simple and low-stress tools. It can make quality cutting tools for light-duty applications, such as punches and chisels.

How to Choose the Right Tool Steel Grades for Your Project

So, how do you choose the right tool steel grades for your project? Having the right grade of steel ensures that you can create the perfect, high-quality tools you need for every task. Choosing the best tool steel all depends on certain factors of your project, including:

• How much wear resistance is needed for your project? If the applications require a lot of friction or abrasion, you need a grade that has a higher hardness and wear resistance.
• The operating temperature at which the tool needs to work. You need a high heat resistance for hot work and high-speed work.
• The machinability you need for the tool. Some tool steels are easier to machine than others, which can cause issues with efficiency.
• The impact resistance you need. Some tools may need to face heavy impacts and shocks.

Our Collection of Quality Tool Steel

At Rapid Metals, we have a wide range of tool steel to suit your needs. We stock high-quality tool steel material that comes in both D2, O1 and silver steel. These are extremely wear-resistant and strong to help you have tools made for heavy-duty applications. You can make a range of tools with our collection, such as punches, dies, cutting tools and industrial knives. Explore our range and find the right size quality tool steel for your project needs. If you can’t find the size required, we also offer a cut-to-size service for you to ensure you have enough material and prevent wastage.

The post The Complete Guide to Tool Steel Grades and Their Uses appeared first on Rapid Metals.

But why is this? And exactly what is copper used for today? Rapid Metals is one of the UK’s leading stockists and suppliers of copper in all sorts of forms. In this blog we’ll explore both the properties of copper and its many practical applications.

Copper Properties and Uses

Copper has been such a versatile and widely used material because of its unique properties. It’s one of the few metals that has practical uses in its pure form (without being modified by mixing with other elements in an alloy). The majority of copper is initially extracted in the form of sulfide ores (ores usually containing less than one per cent copper by weight) or oxides, which are then refined and smelted to produce pure or near-pure copper. But copper can also occur naturally in its pure form.

This is why it started to be used and worked by humans as far back as 10,000 years ago. It was also the first metal to be cast in moulds (6000 years ago) and the first to be used as the basis of a deliberately-manufactured alloy (when copper was mixed with tin to create bronze about 5500 years ago). Copper was useful and desirable to ancient people for many of the same reasons we still use about 23 million tons of it each year in the 2020s – it’s highly malleable and ductile, it’s corrosion-resistant and an excellent conductor of heat and electricity. It also has an attractive pink/orange colour and shines up when polished and cleaned, and is readily recyclable.

Electrical and Electronic Applications

If we were to try and pick copper’s single most important use, it would be for electrical applications. Copper’s combination of excellent electrical conductivity, low weight and high ductility (ability to be drawn into thin strands and wires) make it ideal for use in wiring and electrical components.

Wiring in homes, offices and factories is nearly always made of copper, as are the high-voltage power lines that carry electricity long distances (these are not insulated – you can often see the distinctive green/blue colour of weathered copper). Since the birth of the electrical era in the 19th century, copper has been the material of choice for the windings of electric motors, generators, transformers and other equipment, making electricity a practical form of power and energy. On a smaller scale, electronic components and circuit boards use copper in televisions, computers, smartphones and other tech gadgets.

Plumbing and Water Systems

Anyone who’s done some DIY or home renovation has almost certainly encountered copper plumbing. Why is copper used in water pipes? Copper is lightweight, ductile, cost effective and corrosion resistant, so it’s ideal for use in the complicated runs of small-diameter pipes found in homes. A big advantage of copper for plumbing is that it is easy to work with – copper pipes can be cut, shaped and joined without specialist tools, even in awkward spaces. It is a good basis for soldering to make joints and add fittings.

Because it doesn’t rust like iron or steel pipes, copper plumbing is much longer lasting and less prone to developing leaks or holes. Iron or steel pipes also tend to turn the water in them dirty with rust without regular flow. By contrast copper pipes don’t ‘leach’ into the water. That resistance to corrosion means that copper pipes don’t need painting or coating for protection. Copper also has antimicrobial properties, so copper pipes inhibit the growth of harmful bacteria in plumbing.

Building and Construction

Builders and architects use copper for more than wiring and plumbing. It has both practical and aesthetic applications on the outside of buildings and as a design statement. Because it is light, workable and weather-resistant, copper has been used for centuries as a roofing material (albeit a relatively expensive one) and is even more often seen in details that mix function and form like gutters, railings, finials and domes.

A distinctive characteristic of copper is that over time and with exposure to the weather it develops a patina. The exposed upper layer of metal reacts with oxygen to form copper oxide, with a distinctive green/blue colour. This seals the metal below, preventing further corrosion.

The exact shade and texture of the patina, where it starts, how it spreads and how quickly it develops all depend on the type of copper used, the prevalent atmospheric and weather conditions, how exposed the copper surface is and a host of other factors. This means that copper roofing or cladding is not only practically effective, but each installation takes on a unique appearance. With proper sealing or regular cleaning, copper cladding can retain its bright natural colour (ranging from rich orange/pink to brassy yellow/gold depending on the grade of copper). No wonder architects like copper so much, and why it appears on so many buildings of all types, styles and ages.

Industrial Machinery and Transportation

Many of the properties of copper that we’ve already mentioned come together to explain why it’s such a common metal in industrial, mechanical and transport applications. Of course, many of these make use of wiring, switches, motors and transformers that we have already mentioned. Electric vehicles require a significant amount of copper for their motors, wiring and control systems.

A single typical battery electric vehicle (BEV) requires around 80kg of copper – nearly three times as much as a conventional internal combustion engine-powered car. In the ten years from 2017, the global demand for copper for vehicle manufacture is predicted to increase by a factor of nine.

Copper’s ductility and excellent heat conductivity make it widely used for industrial and vehicular heat exchangers such as radiators, oil coolers, intercoolers and coolers for marine engines.

Household and Decorative Uses

You can also find copper in household items and artworks. Thermal conductivity makes copper a superior choice for cookware such as pots and pans – they not only heat up and cool down quickly, allowing accurate and responsive temperature control while cooking, but they also allow heat to spread evenly, rather than developing hot spots.

There are also copper’s antibacterial properties to consider. And, by no means unimportant, copper also looks great in a kitchen thanks to its rich, warm colour and shine. All these reasons are why copper is also used for things in the home beyond kitchenware, such as door handles, railings, sinks and bathroom fixtures.

Whether you’re a plumber, an architect, an engineer or a hobbyist, copper can be a useful and vital material. The uses of copper metal are diverse and widespread—from the homes we live in to the machines that drive our industries. Thanks to the many useful properties of copper metal, it continues to be indispensable in our daily lives and the wider world.

Rapid Metals can supply many types of copper products in our online shop. Flat strips, copper sheet, round bar and tube or square bar – we can supply all this in a wide range of dimensions and custom lengths. Depending on the size of your order and your location, you can pick up your copper in one of our two stores in the Midlands, we can deliver, or we’ll send it by courier. Contact us to discuss your needs and find out more about our services.

The post The Common Uses of Copper appeared first on Rapid Metals.

But stainless steel isn’t a single material. It’s a family of similar steels, all featuring added amounts of chromium when compared to standard steel. This is what makes it stainless – resistant to corrosion. But beyond that, there are many varieties and grades of stainless steel. Each has a different composition and different properties to suit it for specific uses.

To help designers, engineers, fabricators and purchasers ensure they get the right stainless steel for the job, there is a standard system of defining stainless steel grades. But what are stainless steel grades? How are they categorised? How do you compare stainless steel grades to decide which is right for your project?

Rapid Metals is one of the UK’s leading metal stockists, including the most commonly used grades of stainless steel. So let us demystify the intricacies of stainless steel grading in this blog.

What Are Stainless Steel Grades?

Stainless steel grades provide a standardised and informative way to describe the chemical makeup and the mechanical properties of stainless steel.

There are several different systems for grading and describing stainless steel in use around the world and across different industries, and there are also some systems that were used in the past but have been superseded.

Officially, the most commonly used grading standard is the Unified Numbering System (UNS), which is a six-digit system that has been adopted by the AISI (American Iron and Steel Institute), the Society of Automotive Engineers (SAE) and the ASTM (American Society for Testing and Materials).

Before that, each of these bodies had its own grading/specification system for stainless steel (and other key materials). The UNS incorporates parts of the older three-digit AISI system, developed in the 1930s, but with the extra pair of digits giving more information. It is still very common to refer to stainless steel by its AISI number outside the most technical and official documentation and situations.

For instance, the most commonly used grade of stainless steel worldwide was classified as ‘304’ under the AISI system. Under the UNS it’s S30400, while a low-carbon variant previously known as 304L is S30403. Because the UNS standard incorporates the older three-digit AISI grade, stainless steel is still widely described, specified, bought and sold under this grading, especially for the most common and versatile types.

How Many Different Grades of Stainless Steel Are There?

There are other grading and standard systems around the world, such as ISO (International Standards Organisation), EN (European Norm), BS (British Standard) and JIS (Japanese Industrial Standards). Every grade of steel sold will have an entry in all these standards, and any good supplier should be able to tell you which of any of these standards apply to its products.

But, around the world, you’re most likely to see stainless steel described by the three digits of the AISI system – ironically the one standard that isn’t officially maintained anymore!

Whichever grading system is used, there are over 150 defined types of stainless steel. However, only around 20 are in common use – the others are for specialised applications.

Under the AISI and UNS grades, stainless steels are grouped into five broad series or families, represented by the first digit of the grade number. All the metals in each series have the same microscopic crystalline structure and thus will have broadly similar mechanical properties. Within each series, the individual grades have varying compositions to give them different qualities to suit them for specific purposes.

Generally, the higher the grade within each family, the better the performance of the stainless steel in terms of corrosion resistance – but higher-grade metals will also be more expensive.

Stainless Steel Grading Explained

1. Austenitic Chromium-Nickel-Manganese Stainless Steel (200 Series)

These are lower-cost grades of stainless steel for use where high corrosion resistance isn’t required. These are ideal for indoor applications that won’t be regularly exposed to weather, moisture, extremes of temperature or corrosive environments. Typical uses include household appliances, furniture fittings and car interior parts.

2. Austenitic Chromium-Nickel Stainless Steel (300 Series)

This is the most widely used family of stainless steels. They usually have good corrosion resistance and are strong, non-magnetic, have good formability and are easy to weld.

Grade 303 stainless steel has sulphur in its composition, which makes it more readily machinable than many other grades of stainless steel. The downside is that the sulphur reduces their corrosion resistance – 303 stainless steel will still be far superior to mild steel, but not as durable or resistant as higher grades of stainless steel. It’s commonly used for making nuts and bolts, precision gears and other mechanical shafts.

Grade 304 stainless steel is the most commonly used stainless steel worldwide. It has reasonable machinability and, unlike 303 grade stainless steel, responds very well to welding. It has good corrosion resistance in all but the harshest usual environments. It’s highly versatile but is particularly used in kitchen equipment and fittings, food preparation machinery and medical environments.

Grade 316 stainless steel is alloyed with molybdenum, giving it improved corrosion resistance and durability even in marine and other corrosive environments. Its resistance to corrosion and pitting even when exposed to harsh chemicals also makes it ideal for applications in the paper, textile and photographic industries.

3. Ferritic & Martensitic Stainless Steel (400 Series)

Stainless steels in the 400 Series have more chromium but less nickel than the 200 and 300 Series grades. This makes them significantly cheaper to buy in bulk. They are magnetic, have good resistance to stress corrosion cracking and can be heat treated for higher strength. However, while they won’t fully corrode away like mild steel, 400 Series grades are prone to localised corrosion and surface pitting in damp or corrosive environments. Automotive exhaust systems, cutlery and culinary knives, surgical instruments and razor blades and industrial ball bearings are common uses of 400 Series stainless steel.

4. Martensitic Stainless Steel (500 and 600 Series)

These are specialist forms of chromium alloy, optimised for durability, strength and stability in high-temperature environments. The 500 Series gains these qualities through its chemical and structural composition, while the 600 Series stainless steel grades are also heat-treated and hardened. These are used in furnaces, turbines, automotive exhausts, aerospace, chemical processing and nuclear reactors.

Choosing the Right Stainless Steel Grade

The right grade depends on the intended environment – will the metal be exposure to moisture, salt or chemicals? Is the structural durability of the metal vital or is only the surface appearance important? Does the surface have to remain entirely free of corrosion?

What are the strength requirements? Are their hygiene considerations or regulations to consider? Can or should the metal be magnetic? And what is the budget or cost allowance?

For instance, where costs must be controlled but stainless steel will only be serving as a surface finish in an indoor environment, 430 stainless steel is ideal. But for a metal that can remain flawless and hygienic when regularly wetted and cleaned, then 304 is the obvious choice. Meanwhile, a section of railing for a yacht is best made out of 316 for its added corrosion resistance in salty environments.

Understanding Stainless Steel Grading

Rapid Metals stocks 303, 304 and 316 stainless steel – as you hopefully now appreciate, this is the right material for a huge variety of non-specialist situations. Our locations in the West Midlands can supply and deliver these stainless steels in many forms – angle, box section, flat, bar (square, round and hex), tube and sheet – cut to custom lengths and in quantities large or small.

We pride ourselves on being able to supply what our customers need, whatever the job. Don’t hesitate to contact us for more information about our stainless steel or our other products.

The post Stainless Steel Grades Explained appeared first on Rapid Metals.

The process can be difficult to understand, which means it can feel impossible to work with the two metals together and prevent the corrosion from happening. Don’t worry, as at Rapid Metals, we understand the challenges many professionals face when creating structures with aluminium and stainless steel. This is why we’ve created this guide to help you understand galvanic corrosion, what happens when it starts and how you can prevent it to make your projects using these metals that little bit easier.

What Is Galvanic Corrosion?

Galvanic corrosion, also known as bimetallic corrosion or dissimilar metal corrosion, is an electrochemical process. This happens when two different metals come into electrical contact with each other and a suitable electrolyte is present, which allows the flow of electricity. When this occurs, it will cause one of the metals to corrode away while the other one stays intact. Both the chemical and electrical processes behind this unique occurrence can be quite complicated to understand. However, it’s essential to wrap your head around them because they have the potential to cause a whole lot of trouble to structures and systems that use different types of metal.

The key aspect to know about galvanic corrosion is that it doesn’t happen between every metal. It’s only something that occurs when there’s electrical contact between a positively charged metal and a negatively charged metal. The positive metal is known as the anode, and the negative metal is referred to as the cathode. This process also only happens when an electrolyte is present, as this is what lets electrons flow and strengthens the electrical contact between the two metals. Once they come into contact, the electrons in the anode will leave and go into the cathode, which is the reason why the anode corrodes away. Since the cathode takes those electrons from the anode, it stays intact with no damage to the metal at all.

Galvanic corrosion doesn’t always happen at the same speed, and the rate of the process can depend on several factors. These include how electrically dissimilar the metals are. The bigger the difference in electron count between them, the larger the rate of electron transfer will be. This means that when this is the case, the galvanic corrosion will be much faster than if the electron count is smaller. As well as this, the presence of an electrolyte, and what it is, will also affect the process. If it occurs in dry conditions with no electrolyte present, the galvanic corrosion process will stop on its own. However, if the metals come into contact with each other in fresh water, then this is an electrolyte that will make the corrosion process that bit faster. If it occurs in salt water, then this is a very effective electrolyte that creates rapid galvanic corrosion.

Galvanic Corrosion and Aluminium Corrosion

A very common type of galvanic corrosion is between aluminium and stainless steel. Every form of steel and aluminium will create a galvanic corrosion process in the right (or even wrong) conditions, but it’s an even bigger problem with aluminium and stainless steel. This isn’t due to their specific individual chemical properties. Instead, it’s due to the ways in which the metals are used together for.

On their own, aluminium and stainless steel offer excellent corrosion resistance, which is what makes them a popular choice to use for many situations. This is especially the case for situations where corrosion-resistant metals need to be used, such as outdoor or marine environments. Both of these situations give the dissimilar metals a chance to be in an electrolyte environment, especially when they’re in seawater, which quickly starts galvanic corrosion. When this happens, the stainless steel becomes the cathode and the aluminium becomes the anode, meaning that the concern with this is the aluminium corrosion that can occur.

Now, it may be easy to wonder how aluminium corrosion can be a problem when it is a metal that’s known for its exceptional corrosion resistance. Yes, aluminium does typically resist corrosion even when it’s exposed to seawater or other corrosives. It’s designed to prevent further corrosion by the surface of the metal reacting with oxygen in the atmosphere. This forms a layer of aluminium oxide that seals the rest of the metal underneath, protecting it from corroding fully. Even though aluminium has this protection, it can’t withstand aluminium corrosion from the galvanic process. This is because it works completely differently from any other environment. When electrolytes and stainless steel are present, the galvanic corrosion process degrades the structure of the aluminium on an atomic level that even a layer of oxide won’t stop it. This leads to all of the aluminium corroding down completely, while no stainless steel corrosion occurs and this metal stays intact with no damage.

As the process works differently and still causes aluminium corrosion, it also means that the usual ways to prevent the metal from corroding don’t actually stop it either. This means that any type of preventative care that works for oxidisation, such as stripping, cleaning and repainting or sealing the surface, won’t even protect the metal. These measures will only be a temporary fix that slows down the process, but the metal will still corrode away. The only way to combat galvanic corrosion between aluminium and stainless steel is to take specific measures to stop and prevent galvanic corrosion from occurring.

How To Prevent Galvanic Corrosion Between Aluminium and Stainless Steel

When it comes to how to prevent galvanic corrosion between aluminium and stainless steel, it can be challenging to ensure that it doesn’t occur. There are many steps you can take to help prevent the process from happening when both metals are being used in an environment where electrolytes are present. It is all about avoiding combinations of the three elements that cause galvanic corrosion, but when you need to process chemicals or operate in salty environments, it isn’t as simple as this.

The key to stopping galvanic corrosion between aluminium and stainless steel is to electrically separate the two metals. It’s important to break the electrical path between the two metals to help prevent the electrons from transferring from the aluminium to the stainless steel, causing aluminium corrosion. This can be done in numerous ways, such as:

• Insulating the metals: Putting an insulator between the two metals to prevent them from connecting can help to break the electrical path between them. This can be done by using plastic washers, rubber gaskets, painted surfaces, coatings, greases or nylon bushings. It’s best to insulate both metals, but just insulating the anode can help to slow the galvanic corrosion process down.
• Coatings: Coating the aluminium and stainless steel can also stop them from connecting electrically. Using dielectric coatings can prevent the process from happening. These create an insulating layer that blocks the electrical path and can come in paints and films. Simply painting the metals can be enough, but you can also use primer or zinc galvanised coatings.
• Eliminating electrolytes: It’s also effective to keep the metal surfaces covered, so that they can stay dry. This prevents standing water from reaching the metals, which carry the electrolytes and fuel the galvanic corrosion process. You can use clamp liners, wear pads or even pipe wraps between the dissimilar metals to eliminate the electrolytes.
• Sacrificial anodes: This is when you protect the anode (aluminium) from the cathode (stainless steel) by using another anode of a less noble material. You can use zinc, as this is less noble than aluminium, and put it in direct metallic contact with the aluminium metal. This will cause the zinc to protect the aluminium because when galvanic corrosion happens, the electrons of the zinc will pull out and transfer to the stainless steel, causing the zinc to corrode instead of the aluminium – hence the name sacrificial anode.
• Plating of galvanising: Plating or galvanising can be a great way to reduce galvanic corrosion. It can help to alter the electrons without completely changing their structure. You can plate the metals with fasteners made from gold, nickel, chrome or carbon steel.

Now that you know about aluminium corrosion due to the galvanic corrosion process, you can consider the environment you’re working with when needing to use aluminium and stainless steel together. If you need to use these two metals in an environment where electrolytes are present, you need to take measures to prevent the process from occurring. Without these necessary measures, you can quickly find that the aluminium becomes corroded, affecting the structure you’re working with and shortening its lifespan. If you don’t protect the aluminium from coming into contact with the stainless steel, then your project can corrode, become damaged or even break.

Whatever your project needs, if it requires the use of stainless steel and aluminium, you can rely on Rapid Metals to provide you with exactly what you’re looking for. We stock various types and lengths of both stainless steel and aluminium to suit your project requirements and create robust, high-quality structures that last. Our aluminium collection includes round, flat, square, sheet, angle and so much more to aid multiple projects. While our stainless steel collection has round, hexagon, square, flat and so much more to suit your needs. Each collection offers high-quality metal that is durable and long-lasting for a strong, flawless finish you can rely on.

The post Simple Ways to Prevent Galvanic Corrosion Between Aluminium and Stainless Steel appeared first on Rapid Metals.

Mild steel is one of the basic industrial materials of the modern world, made in huge quantities and used for countless purposes by everyone and everything, from the largest car manufacturers and grand civil engineering to hobbyist engineers and fabricators in a back garden workshop.

There are actually many different types of mild steel, and what a ‘type’ is can be defined in many different ways. Let Rapid Metals, one of the UK’s leading metal stockists and suppliers, explain what types of mild steel there are and what they are used for.

Grades of Mild Steel

When considering the different types of mild steel, one of the clearest ways of defining those types is by looking at the different grades. There are many international standards and grading systems for steel, but the most widely used is the European one, which assigns each grade a number (increasing with carbon content) after the initials ‘En’. When looking at different types of mild steel grades, we’ll only be looking at low numbers below 10.

Starting at the bottom, En1a is a type of mild steel specifically formulated to be ‘free machining’ – with a very low carbon content and added sulphur or lead gives it excellent, smooth and precise machining properties. It is well suited to use in lathes and CNC machines. It is ideal for the rapid production of turned parts such as nuts and bolts, hydraulic fittings, pins and low-stress shafts. The very composition that gives En1a its good machineability also gives it very poor welding characteristics, and it is not suitable for situations of high mechanical or thermal stress.

En3b is the grade for what is probably one of the most versatile and commonly used types of mild steel. It is suitable for a huge range of applications, so long as the ultimate stresses are not high. These uses can include structural beams, vehicle chassis, threaded bars, machinery components and casings, fasteners like nuts and bolts. En3b has good machineability and weldability, making it a very common choice for all kinds of general fabrication and engineering.

For a type of mild steel offering greater strength and hardness, there is En8. It has a higher carbon content than En3 (typically 0.4%, or more than double that of En3), which gives it higher tensile strength and improved hardness. In use cases like axles, cranks, bolts and studs, locking keys, rollers and other parts for machinery and equipment, En8 can offer the performance needed without going to the expense of engineering steel alloys.

Finishes of Mild Steel

Mild steel can also be classified by the finish of the metal, and that finish can either be deliberately applied or as a result of the process by which the product was made.

When considering the uses and types of mild steel, the finish also affects the properties of the steel, and so also the applications for which it’s best suited.

Cold reduced mild steel is rolled and flattened to sheets when cold (i.e. at room temperature) – it’s more normal for the metal to be worked hot. This produces strong metal with a smooth finish that makes a suitable base for all kinds of finishes and surface applications. But it’s far less ductile than other types of mild steel – so it’s good for construction and structural purposes.

The more commonly used type of mild steel is hot rolled. Working and forming the steel when hot means it is more ductile and malleable, producing a strong and versatile product with good welding, cutting and drilling characteristics. It has a rougher finish than other finishes, often with a black or blue/grey colour from the heating. It can require further finishing or coating to have an attractive appearance. The metal shrinks and deforms slightly as it cools after finishing, so it shouldn’t be used where absolute dimensional accuracy and consistency are required. But it’s a good choice for fabrication, construction and engineering, where the unfinished metal won’t be visible.

A disadvantage of all forms of mild steel is that they are prone to rusting if not properly protected. One of the most effective forms of protection is to have mild steel hot-dip galvanised. The metal is placed in a bath of molten zinc. This reacts with the oxygen in the atmosphere, forming a strong surface layer of zinc oxide all around the mild steel, preventing corrosion of the metal. The galvanised surface is deep and tough enough to withstand weathering and mild abrasion or scratching. This all makes galvanised mild steel ideal for outdoor or all-weather structures such as building frames, vehicle and trailer parts and fence posts and wires. Mild steel can also be protected with zinc by electroplating – this produces a thinner, smoother and more accurate coating, so it is used for protecting the threads and heads of bolts, nuts, screws and other fasteners.

For a type of mild steel with a distinctive functional finish, there’s also tread plate. This is a form of cold rolled mild steel, where one of the rollers has the distinctive cross-hatch diamond pattern embossed into it. This works one side of the metal, leaving the high-grip texture suitable for stairs and walkways, trailer and vehicle floor plates and industrial aesthetic touches.

Mild steel in round bar forms can be bright drawn, which is a form of cold finishing. As well as being drawn (pulled and extruded through a narrow die), the round bar is turned, ground and polished to produce a bright, smooth, shiny and extremely accurate surface finish. This makes them ideal as the basis for parts like shafts, axles, bearings, pins, pumping elements, locks and more.

Forms of Mild Steel

Different types of mild steel can also be classified by their form, with different forms being suitable for different uses, such as:

• Angle:Formed with a right-angle bend in long strips, used for structural reinforcement such as building and roof frames, heavy-duty industrial racking and shelving and outdoor structures.
• Box:A versatile section combining strength and minimal weight, steel box sections are used for structural frameworks in buildings and vehicles, as well as pieces like furniture, gates and fences.
• Channel:Effectively ‘half’ a box, a mild steel channel serves many structural purposes, such as door and window lintels and floor joists. This form can also be used for structural frames for vehicles and machinery, railings and signposts.
• Cut Block:Supplied as a regular solid block, mild steel can be cut, milled, machined and otherwise finished into almost any number of objects.
• Flat:Mild steel flat bar is often used for structural supports and bracing. It can be made into various types of mechanical components and fittings, general fabrication and also for decorative metalwork.
• Hexagon:Hexagonal-section is a type of mild steel with some specific uses – especially as the centre spindle for the rollers on conveyor systems and similar machinery. They can also be used to make bolt and screw heads, or for decorative pieces due to their distinctive shape.
• Oval Tube:Oval tube is one of the other types of mild steel with a few specific uses – it’s ideal for wall rails, balustrades, clothes rails, shelving and similar applications.
• Round:Mild steel in round bars has almost countless applications. With relatively little further machining, it can be used for rollers, dowels and many other machinery parts. It can form driveshafts, axles and spindles, or it can be turned down and cut to make pins, screws, bolts and other fasteners. It can be used ‘as is’ for structural purposes.
• Round Tube:Round tube mild steel combines strength, accuracy and low weight. It can be used for making hydraulic and plumbing fittings, pipework, tools and dies, structural supports, frameworks, fencing, railings and more.
• Sheet:Sheet is the basic form of how much of the world’s mild steel is made and used. It can be put to many uses, from car body panels and shipping containers to forming tools and utensils and making cabinets.
• Square:Square bar mild steel has generally the same applications as round bar, although it is not as suitable for making fixings and bearings. It serves more structural purposes such as frameworks, general fabrication, furniture and ornamental metalwork.
• Threaded Rod:While round bar can have threads cut in them, mild steel can also be supplied with threads cut and zinc coating applied, making it ready for cutting into screws and bolts of any length.

Every Vital Type of Mild Steel at Rapid Metals

We hope this blog has revealed and explained the many types and uses of mild steel – one of the fundamental materials of the modern world. All these different types of mild steel, whether by grade, finish or form, are available in Rapid Metals’ online store, to be ordered cut to size and in a wide selection of diameters, finishes and dimensions.

The post Different Types of Mild Steel and Their Common Uses appeared first on Rapid Metals.

Read this blog from Rapid Metals, one of the UK’s leading stockists and suppliers of all kinds of metal, including cast iron, to learn more about cast iron and the typical uses of cast iron.

What is Cast Iron?

Despite its name, cast iron is not pure iron that has been cast. What’s more, cast iron has less iron in it than steel!

Cast iron is actually an alloy – a mixture of a metallic element and another. In this case, it is iron alloyed with carbon, just like steel. While steel has a carbon content of less than 2.0 per cent, if the carbon content exceeds 2.0 per cent, the result is classified as cast iron.

In reality, most cast iron produced has a carbon content of between 2.0% and 3.5%, as higher carbon content makes the cast iron unusably soft and brittle.

Why is it Called Cast Iron?

So cast iron isn’t pure iron, and is less ‘iron’ than steel. Why is it called cast iron? It’s because of cast iron’s antiquity. It was the first iron alloy to be reliably manufactured, many thousands of years ago. Ancient wood- or charcoal-fuelled furnaces produced a lot of soot (carbon) and offered only limited control of the air supply and temperature.

This meant that iron ore processed in them inevitably had a high carbon content. Cast iron represented the form of processed iron with the lowest carbon content for millennia. That relatively low carbon content (when compared to other forms of processed iron) gave it greater fluidity, making it unsuitable for forging but ideal for casting. Hence why this particular proportion of iron and carbon came to be known as cast iron.

Later developments in metallurgy, fuels and furnace design allowed the carbon content of an iron/carbon alloy to be more carefully controlled below 2.0 per cent. These metals had such different properties from cast iron that they were given a new name – steel.

While both cast iron and steel are alloys and have the same basic constituents, just in slightly different proportions, their physical and mechanical properties are sufficiently different that they have always been classed as different materials, not just grades of the same alloy.

How is Cast Iron Made?

Given how early in human history cast iron was first produced, it’s not surprising that its manufacturing process is simple. It requires iron ore to be heated in a furnace to between 1200 and 1300 degrees Centigrade until the iron content becomes molten and separates from the other materials in the ore (which usually form slag). The molten iron is poured out of the furnace and allowed to cool and harden into ingots. This is the form that cast iron is stored and transported in.

When needed to make finished products, the cast iron ingots are reheated and melted again. The liquid metal is then poured and cast into the final moulds, forming whatever the required shape. In this second melting and pouring stage, other materials can be added to the molten cast iron to give it particular properties. For instance, graphite nodules will improve the resulting metal’s ductility, while adding graphite flakes improves machineability.

Modern processes have advanced on this traditional method, and cast iron is now usually produced as part of the steel-making process. Cast iron is now made in a blast furnace, where iron ore, coke and limestone are processed at temperatures of around 1700 degrees Centigrade. Most of the slag and impurities are either burnt, boiled or floated off the molten metal. This will result in an alloy with around 4 per cent carbon content. This molten metal is ‘tapped’ from the blast furnace. Most goes on to be further processed to make steel, but for cast iron, it is transferred to an electric cupola furnace for further heating and refining, to become cast iron ingots.

What are the Properties of Cast Iron?

Although no longer the premier metal alloy available, cast iron remains a widely used and commonly encountered material. Even within the array of modern alloys, cast iron has many desirable properties. These include:

• The castability that gives it its name
• Good fluidity
• Excellent machineability
• Good compressive strength
• Strong wear resistance
• Low cost in bulk

Limitations of cast iron include relatively low tensile strength and high brittleness.

Uses of Cast Iron in Construction

When mass production of high-quality cast iron became possible in the 18th century, it led to a boom in the use of cast iron in construction. Cast iron offered greater strength in compression than wood and was lighter for a given load capacity. It could be cast into specific, complex shapes at low cost.

Cast iron’s poor tensile strength means it doesn’t resist torsional, tension or bending loads well, which limits its suitability as a structural material. In the 19th century, there were several infamous collapses of buildings and bridges where cast iron was used incorrectly.

However, cast iron’s good compressive strength means it is well-suited to bearing steady, unidirectional loads in compression, such as in vertical pillars. Steel and concrete quickly replaced cast iron as a primary structural material when they were developed.

But because it can be easily formed into complex shapes, cast iron was still a popular choice for decorative architectural elements that did not handle significant loads, such as railings, fences, balconies, facades, crests and finials. It also remained a popular choice for making greenhouses and conservatories, since it could be cast into lightweight, graceful shapes and didn’t have to support heavy loads.

Common Uses of Cast Iron

One of the breakthroughs in modern cast iron came in the 18th century when Abraham Darby developed a way of making thin, lightweight pots and kettles from cast iron. Cookware is still a very common use of cast iron, with skillets and pans of cast iron being preferred by many professional and keen cooks because of their durability and the way they evenly distribute and retain heat.

Another use of cast iron that most of us will see every day is for manhole covers, which are still often made of cast iron because it can be cost-effectively cast and finished to the required strength, has good inherent corrosion resistance and can withstand the load of passing traffic.

The automotive industry remains a large user of cast iron. The material’s combination of strength and machineability with low cost makes it a typical choice for engine blocks and cylinder heads, as well as parts like brake discs where durability, the ability to be mass produced in volume at low cost and temperature resistance are required. Other casings, shafts, gears and chains may be made of cast iron.

Cast iron is still chosen for structural purposes, especially columns, to take advantage of its compressive strength. Decorative fittings and components are also still often made from cast iron, either in restoring historic properties or in contemporary forms. Another domestic use of cast iron is in stoves, fire grates and fireplace surrounds, because of its durability, ease of being formed into complex and attractive shapes and its heat retention properties.

Cast Iron from Rapid Metals

Rapid Metals can supply high-quality cast iron, as G250 (also classed as BS1452) grade continuous cast grey iron bar.

The post The Common Uses of Cast Iron appeared first on Rapid Metals.