STEP DRILL 3-20MM HSS 4241, WITH TITANIUM COATED, HEX SHANK, DRILL 4-12 MM: 4, 6, 8, 10, 12 MM, 3-12MM: 3-4-5-6-7-8-9-10-11-12, 4-20MM: 4-6-8-10-12-14-16-18-20MM
