Alloy Steel (20Cr, 20CrMo, 30CrMo, 35CrMo, 42CrMo, etc): Alloy steels encompass a wide range of iron-based metals which contain higher levels of chromium that do not exceed 3.99%. metals that contain greater amounts of chromium are classified either as tool steels or stainless steels. Alloy steels vary in their alloying elements which determine the properties of a particular material.
