UNC, Coarse Thread, Plain Finish, 125 psi minimum tensile strength, for high temperature and pressure applications. 1/2"-13 x 1 1/2" thru 1 1/4"-8 x 8".

A194 Grade 2H Heavy Hex Nut, USS (Coarse) Thread, 1/4"-20 TPI through 3 1/2"-8 TPI. For use with any low carbon, heat-treated bolt or screw.

A194 Grade 2H Heavy Hex Nut, USS (Coarse) and UN8 Class 2B, Hot Dipped Galvanized, 3/8" -16 TPI through 3" -8 TPI. Typically, fasteners are galvanized for corrosion protection.

A563 Grade DH Heavy Hex Nut (USA), heat treated USS (Coarse) thread in plain finish. 1/2"-13 through 1"-8