If you're looking for an industrial or heavy duty caster, you've no doubt come across the term Semi Steel. And, unless you've got a background in metallurgy, chances are you're not sure what it is.
As is out of, semi steel is actually a type of cast iron, with steel scrap thrown in the mixture for good measure. In fact, most semi-steel has quite a bit of steel scrap in it. The result is an alloy that is Excellent for use as casters, for a variety of reasons. Semi steel features easy castability, low cost, and machinability, just as cast iron it. It has also increased strength, impact resistance, and ductility from the steel. A perfect balance of cost effective strength for many medium and heavy duty casters.