Stainless Steel

Materials

Why choose us for Stainless Steel services?

We’re experts at handling a wide range of materials, and one of the reasons for this is that it enables us to offer the complete solution to our clients. Whether we’re working on a design that they bring to us, or helping to create that design in the first place, we can do so in the knowledge that we can handle the subsequent prototyping and production without having to turn to third-party providers.

One of the reasons for this is that we have a team of expert technicians and a set of state of the art facilities to deliver processes which include machining, laser cutting, forming, welding and polishing. Another reason why we can provide a comprehensive service is that we can work with a wide range of materials, including specialist options such as stainless steel.

What have we used Stainless Steel for?

Auto polished brightware, Interior and exterior
Auto bumper
Auto matrix radiator grills
Marine polished brightware
Lockers and tanks
Brackets
Fabrication
Bezels

stainless steel stainless steel exhaust

What is Stainless Steel?

The description ‘stainless steel’ refers to a number of alloys which are all resistant to corrosion. In other words, they won’t rust or stain. Like normal steel, stainless steels are iron-based alloys, with the difference being that they all contain a minimum of 10.5% Chromium. This means that the finished products all have a clear oxide protective layer which is self-healing.

The grade of stainless steel to be used – which is a way of measuring the degree of corrosion resistance it will offer – varies depending upon the environment in which the stainless steel will be operating. Our clients working in the marine sector, for example, will require stainless steel components made from the most corrosion resistant grade of stainless steel possible.

What are the different types of Stainless Steel and what are they used for?

Different types of stainless steel – known as ‘families’ – are created by adding other elements alongside Chromium. These families are austenitic, ferritic, martensitic and duplex. Each family has its own set of properties, and common uses for each include the following:

Martensitic
Stainless Steels

Cutlery
Blades
Surgical instruments
Springs
Fasteners

Duplex
Stainless Steels

Marine applications
Heat exchangers
Food pickling plants
Desalination plants
Off-shore gas and oil installations
Chemical and petrochemical plants

Austenitic Stainless Steels

Kitchen sinks, Gutters, Doors and Windows, Roofing and cladding, Food processing equipment, Chemical tanks, Food preparation areas & Ovens.

Austenitic stainless steel is one of four main categories of stainless steel and is one of the most frequently used. This alloy appears within the 200 and 300 series of stainless steel alloys and is largely composed of iron, chromium, and nickel in varying percentages. Some of the most common grades of austenitic steel are Grade 304 and 316, which are used for numerous commercial and industry-specific items.

Because of the versatile properties of stainless steel, such as corrosion resistance and durability, it finds use in some form within most industries. 

Austenitic steel is considered general-purpose steel and has a multitude of applications from screws and cutters for industrial use, to culinary cookware and cutlery, and the trims and grills of automotive vehicles.

Austenitic steel is moreover a type of surgical steel, used within the medical field; it is low maintenance and easy to clean, used for instruments such as hypodermic needles and forceps. Medical-grade stainless steel may also be used for piercings.

The properties of austenitic stainless steel are dependent on the grade of steel. However, austenitic steel is renowned for its high chromium content, giving it an overall excellent level of resistance to corrosion – hence its definition as a stainless steel. Other characteristics include great strength and durability, as well as good ductility and machinery.

Austenitic steel is not heat treatable and is generally cold worked. 

Austenitic stainless steel is made by adding nickel to an iron, carbon, and chromium solution (the metals compromising stainless steel). However, it is the austenite crystalline structure achieved during creation which determines it to be austenitic steel.

The exact percentages of the metals within its composition, as well as other subsidiary elements, and the subsequent work it undergoes, such as heat treatment, all determine the grade of the austenitic steel.

Certain stainless steels can be more easily welded than others. Austenitic stainless steel is one of these steels, and has good weldability by most welding methods. Moreover, it does not require treatment after welding.

A stainless steel is categorised by its corrosion resistance; however, under certain conditions, stainless steel will rust. The composition of austenitic steel means it is protected from rusting quickly and easily, how it will rust if exposed to chemicals such as certain acids or chlorides, and moist or hot environments, for great lengths of time.

A steel must be composed of at least 50% iron – the element which gives the steel its magnetic property; magnetism is also determined by the structure of the stainless steel – it must be martensitic or ferritic.

It is because of this latter variable that most types of austenitic stainless steel are not magnetic. An austenitic steel has an austenitic crystalline structure, though this can be modified during cold working into a martensitic in order to make it magnetic.

Ferritic Stainless Steels

Vehicle exhausts, Domestic appliances, Cooking utensils & Fuel lines

Ferritic stainless steel is a series of stainless steel alloy – the 400 series – as categorised by its structure and elements. Ferritic stainless steel is defined by the high amounts of chromium within it, and low levels of carbon.

It is the second most popular alloy of stainless steel, following austenitic, due to its affordability and versatile properties. The affordability of ferritic is rooted in the lack of nickel within its structure, which makes it a preferable alternative to austenitic steel, which contains nickel, in many cases.

Ferritic stainless steel has a plethora of applications but is notably found in consumer goods and the automotive industry. The percentage of metals within its composition determines the application.

Within the automotive industry, ferritic steel can be used to create a stainless steel exhaust system and fuel lines, due to its corrosion resistance and durability.

Stainless steel cooking utensils are often made from ferritic steel, due to its thermal conductivity. It can also be used for sinks, dishwashers, and microwave oven componentry, within the kitchen.

Ferritic stainless steel properties are dependent on the exact metallic composition of the alloy; they are divided by their compositions, and thus properties, into five groups. Generally speaking, ferritic steel has good corrosion resistance, strength, and ductility.

However, when comparing some properties such as strength to austenitic steel, ferritic steel is often considered secondary. It moreover is not as substantial if exposed to extreme temperatures, both high and sub-zero.

Ferritic stainless steel is made by incorporating higher levels of chromium into an iron solution.

The ferrite microstructure of the stainless steel involves an iron atom at the centre and at each corner and very little carbon. This is known as a body-centred cubic structure.

Ferritic stainless steel is weldable, though this is often undertaken using thin sheets of the alloy, since some grades can have poor weldability.

Ferritic steel is typically not as easily welded as austenitic, and can crack under high temperatures when using thick sections.

Whether or not ferritic steel rusts depends on the metallic composition of the alloy, or the percentage of metals within its composition.

Categorised into five groupings, Group 1 contains the least chromium out of the ferritic steel series, meaning it is more likely to rust over a period of time. This is because chromium, when it reacts with oxygen forms a protective layer over the metal which is corrosion resistant. On the other hand, Group 5 contains the highest percentage of chromium and has the best rust resistance.

Ferritic steel is magnetic, setting it apart from austenitic stainless steel. Ferritic steel has a central iron atom in its grain structure which grants it magnetic properties.

This is alluded to within the name ‘ferritic’, stemming from ‘ferrous’ – which means it has iron within its composition.

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