Crown Bolt 00640 1/2 Inch-13 x 3-1/2 Inch Coarse Thread Zinc-Plated Steel Hex Bolts, 25-Count Zinc-plated 1/2 inch-13 x 3-1/2 inch hex bolts For general applications 1/2 inch-13 body diameter and thread pitch 3-1/2-inch fastener length Zinc-plated finish