Carriage Bolt, Inch, Neck Type Square, Basic Material Steel, Material Grade Grade A, Fastener Finish Plain, Dia./Thread Size 3/8 In.-16, Fastener Length 3 1/2 in, Fastener Thread Direction Right Hand, Fastener Thread Type UNC (Coarse), ASME B18.5, Drill Size 3/8 in, Head Dia. 0.782 in to 0.844 in, Head Height 13/64 in, Head Type Round, Square Height 0.188 in to 0.219 in, Square Width 0.368 in to 0.388 in, Tensile Strength 74,000 psi, For Use With Grade 2 Hex Nuts, Package Quantity 25