Chrome vanadium steel* with a satin finish body and highly polished heads, with a 15° offset. DIN 3110: 1/4" x 5/16" to 1 5/16" x 1 5/8" AF. ASME B107.39: 1 7/16" x 1 5/8" to 1 13/16" x 2" AF. *1 7/16" x 1 5/8", 1 1/2" x 1 5/8", 1 11/16" x 1 7/8", 1 13/16" x 2" made from drop forged carbon steel.