Stainless steel is an alloy steel that contains a minimum of 10.5% chromium and 6% nickel, molybdenum, and niobium. Compared to general steel, stainless steel does not easily corrode, and rust. Martensitic grades are Cr-Fe alloys with 10.5-17% chromium and medium content of carbon, hardenable by quenching and tempering. They are magnetic, have good strength and high hardness, but are fragile and hard to form and weld which has been mostly used in knives and blades. Type 420 (S42000) is the commonly used grades. At WLD Steel, Martensitic stainless steel products are available in an extensive range of forms, grades, finishes, gauges, widths, and lengths.