Viking SP-18TDM 18-piece Premium Metric Tap and Drill Set features 9 common thread sizes of Type 21-UB Spiral Point Plug Taps in Coarse Thread Pitch from M2.5-.45 through M12.-1.75, and the matching Type 643-UB Pilot Drill Bits. Pilot bits feature a 135° Split Point for fast penetration and easy starting without the use of a center punch or pilot bit. Bits and Taps feature a gold oxide surface treatment which provides additional lubricity, reduces wear and assists swarf in traveling along the flutes with less resistance as it exits the hole during drilling and tapping. These quality tools are highly recommended for use in work hardening grades of stainless steel and other tough and hard metal drilling and tapping applications. Bits and Taps are of one piece solid construction, and are manufactured in the USA of special Hi-moly tool steel. Set includes tap drill pilot sizes (mm) 2.05, 2.50, 2.90, 3.30, 4.20 5.00, 6.70, 8.50 & 10.20 and Spiral Point Plug Tap sizes (mm) 2.5-.45, 3.0-.50, 3.5-.60, 4.0-.70, 5.0-.80, 6.0-1.00, 8.0-1.25, 10.0-1.50 & 12.0-1.75 and a metal index storage case.