... nickel and chrome 3. Meet and exceed ANSI standard 1. made of heat-treated Chrome Vanadium steeel for strength exceeding international specifications2 ... , 10MM, 11MM, 12MM, 13MM, 14MM, 15MMSAE= 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16 ...