According to its functions, stainless-steel can be divided right into non-magnetic stainless-steel, complimentary reducing stainless-steel, low-temperature stainless-steel, high toughness stainless steel. Enhancement of 0.2 ~ 0.4% sulfur and selenium as pollutant aspects in stainless steel can improve the reducing efficiency of stainless steel since they reduce the durability of stainless-steel. For instance, the influence value of 18-8 stainless steel can get to 30kg/cm ². The influence value of steel 18-8 including 0.31% sulfur (0.084% C, 18.15% Cr, 9.25% Ni) is 1.8 kg/ centimeters ². The influence value of steel 18-8 having 0.22% selenium (0.094% C, 18.4% Cr, 9% Ni) is 3.24 kg/ centimeters ². Today below we have figured out the frequently utilized totally free cutting stainless steel and their chemical composition.