... 3. heat treated 1. Professional 1/2" 28 pcs chrome vanaidum socket set2.Content:22pcs 1/2 " DR metric socket ... , 9, 10, 11,12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24,26, 27,28, 30 ... ,50BV30, CR-V 4. Surface finish: mirror finish, phosphating, chrome plated, electrophoresis, and Zinc.5. Process: heat treatment, drop forged ... and best costs. Professional 1/2" 28 pcs chrome vanadium socket set