System of Measurement Inch Heavy Hex Bolt Head Type - Bolts Hex Basic Material Steel Material Grade A307B Fastener Finish Plain Dia./Thread Size 1/2 In.-13 Fastener Length 2 1/4 in Fastener Thread Direction Right Hand Fastener Thread Type UNC (Coarse) Fastener Industry Standards ASME B18.2.1 Min Thread Length 1 1/4 in Fastener Thread Style Partially Threaded Head Height 11/32 in Head Width 7/8 in Package Quantity 25