Choosing the right steel grade

THERE are probably as many different steel and pipe products on offer as there are different uses for them. While steel manufacturers have a variety specs for steel and pipe, here are some broad categories to help users make informed decisions.

All steel and pipe are alloys in which iron is mixed with carbon and other elements. Steels are therefore described as mild, medium- or high-carbon steels, depending on the percentage carbon they contain. The higher the carbon content, the harder the steel will be.

Metals such as nickel and chromium can also be added to produce alloy steels, for example stainless steel which is used in high-end, quality steel products. Galvanised steel is coated with zinc to prevent corrosion for use in roof sheeting, for example.

Galvanised pipe is also mainly used in construction, while corrugated steel pipes will be used more often for drainage, sewer and transportation. Seamless pipe, made from high-quality steel is used for steam boilers and pipelines.

Steel products can be divided into two groups – flat and long products. Flat steel is used in the manufacture of cars, electrical products, sheeting, coils and pipes. Long products, on the other hand, are mainly used in construction.

Steel and pipe buyers will also come across the terms hot rolled and cold rolled steel. This refers to the heat treatment given during the production process, which has an impact on the qualities of the product. Cold rolled products are normally harder and more brittle, while hot rolled steel and pipe will be softer.

In addition to the different qualities of steel and pipe products, they are also available in a wide variety of sizes and thicknesses.