The hex head cap screw is a common fastener in construction and machine assembly. - The screw head is designed to fit a ratchet or spanner torque wrench for tightening to exact specifications. - As an alternative to welds or rivets, cap screw fasteners offer easy disassembly for repairs and maintenance. - Grade 5 screws are often used in small engines. Material / Steel, Steel Material Grade/Class / Grade 5 Finish / Chrome Plated Thread Size / 3/8"-16 Thread Direction / Right Hand Fastener Length / 1 1/2 in Minimum Thread Length / 1 in Head Width / 9/16 in Head Height / 15/64 in Drive / Hex Drive Size / 9/16 in Tensile Strength / 120,000 psi Rockwell Hardness / HRC25 Dimensional Standards / ASME B18.2.1 Material Quality Standard / SAE J429 System of Measurement / Inch Overall Length / 1 1/2 in Thread Fit / 2A Thread Style / Partially Threaded Type / Hex Head Cap Screw Head Style / Hex Thread Pitch / Partially Threaded Thread Type / Coarse