Flange Bolts Dimensional Standards ASME B18.2.1 Drive Hex Drive Size 5/16 in Fastener Length 1 1/2 in Finish Black Oxide Flange Diameter 11/16 in Flange Type Standard Head Height 5/16 in Head Width 1/2 in Manufacturer Location Globally Sourced Material Steel Material Grade/Class Grade 8 Material Quality Standards SAE J429 Minimum Thread Length 7/8 in Pack Size Small Pack System of Measurement Inch Tensile Strength 150 000 psi Thread Size 5/16 In.-18