Carriage Bolt Inch Neck Type Square Basic Material Steel Material Grade Grade A Fastener Finish Zinc Plated Dia/Thread Size 3/8 In.-16 Fastener Length 4 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 Zinc Nuts Package Quantity 25