Flange Bolts Dimensional Standards ASME B18.2.1 Drive Hex Drive Size 5/8 in Fastener Length 2 1/2 in Finish Phosphate and Oil Flange Diameter 1 21/64 in Flange Type Standard Head Height 5/8 in Head Width 15/16 in Manufacturer Location Globally Sourced Material Steel Material Grade/Class Grade 8 Material Quality Standards SAE J429 Minimum Thread Length 1 1/2 in Pack Size Small Pack System of Measurement Inch Tensile Strength 150 000 psi Thread Size 5/8 In.-11