This 1/2" Drive Standard Length Hex Driver Socket 3/8" Bit is manufactured to the highest tolerances and specifications for straightness, concentricity, and precise tip fit to the fastener. Bit is manufactured from high alloy steel using the most up-to-date manufacturing process and heat treat to prevent shattering and premature bit wear. The bit is retained in the bit holder by a set screw that locks securely into a groove on the bit for positive bit retention as well as simple, easy bit replacement. A broached hex in the bit holder allows for higher torque loads. EYE-D™ markings optimize size visibility (no EYE-D™ markings on A suffix bit sockets).