SKF 280 is a proprietary form of BS 6258 stainless steel. SKF 280's composition is a trade secret and is primarily used in the manufacture of various bearings that need to have hardness, machinablity and corrosion resistance. SKF 280 is a member of the micro alloy family of steels due to the precise proportions of various alloying elements.
In terms of chemistry, SKF 280 steel is a medium-carbon steel with specific amounts of elements. Since SKF 280 is a proprietary form of steel, BS 6258 is the most closely matched "generic" steel. BS 6258 contains carbon (.03 to .2 per cent), silicon (1.0 to 1.5 per cent), manganese (1 to 2 per cent), phosphorous (.04 to .045 per cent), sulphur (.03 per cent), chromium (1 to 24 per cent), molybdenum (2 to 3 per cent) and nickel (.5 to 22 per cent). It may also have small amount of titanium in some alloys.
The primary property of SKF 280 steel is its extreme corrosion resistance. With an unusually high amount of chromium and nickel in the steel, it is resistant to many forms of corrosion that would otherwise destroy most other steels. There is even a patent on using SKF 280 as a pipe material in oil wells with high concentrations of hydrochloric acid. The steel also has increased machinability as evidenced by its use as a bearing material.
Since SKF 280 is a proprietary steel, the cost of the material is often higher than comparable steels, such as BS 6258. However, its performance makes it a preferred material in the bearings industry, in piping and as a hollow bar material.