Product Specification Socket caps have a small cylindrical head with tall vertical sides. Allen (hex socket) drive is a six-sided recess for use with an allen wrench (hex key). System of Measurement : Inch Thread Diameter : 5/16" Head Diameter : 15/32" Head Height : 5/16" Screw Length : 1" Allen Hex Drive : 1/4" High Quality Material Stainless Steel 18-8 (A2-70) Package Included 25 x Socket Head Cap Bolts/Screws 5/16-18 x 1 Inch Warranty MewuDecor hardware has the highest quality on the market. Buy with confidence. Money back or exchange guarranteed.