Socket Set Screw Head Type Square Point Type Cup System of Measurement Inch Thread Size 5/16 In.-18 Overall Length 1 1/4 in Drive Type External Square Drive Size 5/16 in Material Steel Finish Plain Pack Size Small Pack Decimal Equivalent 0.312 in Dimensional Standards ASME B18.6.2 Head Height 0.234 in Head Width 5/16 in Package Quantity 100