Chrome vanadium steel nut driver set for use with power drills. 1/4″ hex drive. Includes sizes 5, 5.5, 6, 7, 8, 9, 10, 11 and 12mm. Compatible with all 6.35mm chucks. Chrome vanadium steel nut driver set for use with power drills. 1/4″ hex drive. Includes sizes 5, 5.5, 6, 7, 8, 9, 10, 11 and 12mm. Compatible with all 6.35mm chucks.