When heat-treated, it achieves the highest hardness values of any stainless steel grade. Type 440 stainless steel, which is available in four grades: 440A, 440B, 440C, and 440F, has good corrosion and abrasion resistance.

In their annealed form, all grades are easy to machine and offer resistance to mild acids, alkalis, foods, freshwater, and air. Stainless Round Bar has different chemical compositions for each grade. The only significant variation between the grades is the amount of Carbon in them.