BBI Structural Bolt, Heavy Partially Threaded, Measurement System: Imperial, 1/2-13 Thread, 1-1/2 in Length Under Head, Medium Carbon Steel, Plain, 1 in Thread Length, Material Specification: ASTM A325 Type 1, 120000 psi Tensile Strength, 24 to 35 HRC Hardness, Hex Head, 0.323 in Drive, UNC Thread, 0.323 in Head, Hex Drive, 0.515 in Shank