Crown Bolt 19167 5/8 Inch-11 x 2-1/8 Inch Zinc-Plated Rod Coupling Nuts, 15-Count Zinc-plated 5/8 inch-11 x 2-1/8 inch rod coupling nut For Industrial Applications 5/8-inch-11 inner diameter Zinc-plated finish Use with bolt of the same diameter, thread pitch, and finish