System of Measurement Inch Heavy Hex Bolt Head Type - Bolts Hex Basic Material Steel Material Grade A307B Fastener Finish Plain Dia./Thread Size 1 In.-8 Fastener Length 2 1/2 in Fastener Thread Direction Right Hand Fastener Thread Type UNC (Coarse) Fastener Industry Standards ASME B18.2.1 Min Thread Length 2 1/4 in Fastener Thread Style Partially Threaded Head Height 43/64 in Head Width 1 5/8 in Package Quantity 5