Item #: 67209965Brand: Holo-KromeModel #: ZP1C72136 Features and Benefits Socket cap head types have large cylindrical heads with recessed hex-shaped drives. They are ideal for applications where limited clearance would not allow the use of wrenches and sockets. Hex socket drive types have a hex-shaped recess in the head and are driven with hex keys or hex socket bits. The driving surface is protected from external damage and provides six sides of contact surface for added torque. Alloy steel is the strongest of all steel types. It has high tensile strength and offers excellent resistance to wear, fatigue and galling. Product Specifications System of Measurement Inch Head Type Socket Cap Drive Type Hex Socket Thread Size (Inch) 5/16-18 Length Measurement Type Length Under Head Length (Inch) 2 Material Alloy Steel Finish/Coating Zinc-Plated Full or Partial Threading Partially Threaded Thread Standard UNC Fastener Standard ASME/ANSI B18.3; ASTM 574 Hex Key Size (Inch) 1/4 Hex Key Size (Decimal Inch) 0.2500