Grade Choice

Stainless steel is not a single specific material: it is the name given to a group of corrosion-resistant steels containing a minimum of 9% chromium. The metal is very durable and posesses a high resistance to corrosion. It is possible to choose a stainless steel which is quite unaffected, even by an aggressive marine atmosphere, and resistant to the attack of many acids. Since it does not affect food and drink, it finds widespread application for catering and food processing equipment, and in brewing and soft dring manufacture. Stainless also retains a high proportion of its strength when heated and therefore is poular for many applications where durability at high temperatures is vital.

There are three main categories of stainless steel - Austenitic, Ferritic, and Martensitic. The easy way to differentiate between these types is by the chemical composition and the typical qualities they have.

AUSTENITIC

This is the most commonly used type, accounting for over 70% of all stainless steel production and usage in the UK.

FERRITIC

Ferritic stainless steel is unique due to the absence of nickel content and the metal has a lower corrosion resistance than austenitic grades. Applications for these types are more restricted. Ferritic grades are sometimes referred to as 'chrome iron'.

MARTENSITIC

Generally only available in bar form for specialised applications such as tools and airplane engine components, where high speed strength is required, martensitic stainless steel has the lowest corrosion resistance of all stainless steel types.