The free cutting steels (sometimes known as free machining steels) contain sulphur and phosphorus. These steels have higher sulphur content than other carbon steels. These steels are used where rapid machining and high quality surface finish after machining is the prime requirement. It may be noted that free cutting steels have low dynamic strength and are more liable to corrosion. These steels are frequently supplied in the cold drawn form and have high tensile strength and hardness but less ductile when compared to ordinary carbon steels.