In the early 1800's, a metallurgist discovered that adding chromium to iron would create an alloy with corrosion resistance against some acids, this marked the beginning of stainless steel. Then in 1890, the invention of an aluminothermic process, which removes carbon from chromium, allowed metallurgists to develop the strong and corrosion resistant stainless steel that we use today. Modern stainless steel can also include other elements to enhance its corrosion resistance, such as nickel, niobium and molybdenum.
Types of stainless steel
There are numerous grades of stainless steel available. 304 is the most common grade used; containing 18% chromium and 8% nickel. 304 grade is a general-purpose stainless steel that is often used for architectural or domestic products where a harsh environment won't affect the product. ABS uses a 316 marine grade stainless steel, as it has a high level of corrosion resistance. Type 316 stainless contains 18% chromium and 10% nickel. It is used on the exterior of both the Petronas Twin Towers and the Jin Mao Building, two of the world's tallest skyscrapers.
Stainless steel is available in a variety of different finishes. Our stainless steel balustrade product is available in either a high polished or a satin finish. Satin finish, or brushed stainless steel as it is commonly known, is a metal with a unidirectional satin finish. The brushing gives the metal a distinctive look, as it retains some of its metallic lustre and is given a pattern of very fine lines parallel to the brushing direction (see FIG 1.0 below). Satin finish is not recommended externally, as it’s slightly abrasive finish means it can tea-stain more easily.
FIG 1.0 Satin Finish
High polished stainless steel creates a mirrored finish, by polishing and buffing the steel using specialist polishing machinery (see FIG 1.1 below). High polished steel is more suitable to external balustrading as it doesn’t tea stain as easily as the satin finish.
FIG 1.1 High Polished
Properties of stainless steel
Stainless steel does not rust or corrode. Stainless usually contains a minimum of 13% chromium, up to 26% for harsh environments, which creates a thin protective layer around the metal when exposed to oxygen. This passivation layer is resistant to water and air. This corrosion resistance makes it ideal for use on balustrading. However, if used in an aggressive environment, i.e. coastal areas, and not properly maintained, stainless steel is prone to ‘tea staining’. Tea staining is where salt and chlorides settle on the surface of the steel and then discolour to resemble rust. This is not rust and can be wiped clean. To find out more on this visit our Tea Staining blog. For details on maintaining your stainless steel balustrade to prevent it from tea staining see our Care and Maintenance blog.
To find out more about our range of stainless steel products see our Products page, visit our showroom at 73 Inspiration Drive, Wangara or call our sales team on 08 9302 1947.