Profile: Sterling Machine Tools specializes in designing, developing, manufacturing, marketing and servicing all types of chucks. We also offer a wide range of lathe chucks. Our chucks are available in 3 jaws, 4 jaws, and 6 jaws. Our chuck body is made of high tensile graded gray cast iron with additional metals for long life, wear resistance and high strength. The body has a hardness of 180 BHN and tensile strength of more than 450 MPA. The pinion is made of forged, high tensile alloy steel having hardened and ground bearing diameters. It is provided with stub teeth which can withstand tightening load. It is specially heat treated to obtain strength.