Insert these taps directly into drills, power screwdrivers, and other tools that accept a 1/4" hex shank. They're made of high-speed steel and are for use on most metal and plastic. All have a plug chamfer with 3-5 chamfered cutting threads, so they're suitable for start-to-finish tapping. When using them to tap closed-end holes, be sure to leave sufficient space at the bottom for chips to accumulate.
Inch
Thread
Drill Bit
Plug Chamfer
Size Lg. Overall
Lg. Size Decimal Size
Equivalent No. of
Flutes Thread
Type Hex Shank
Size Each
Uncoated High-Speed Steel
1/4"-20 11/16" 1 17/32" 7 ga. 0.201" 3 UNC 1/4" 1021N11 $18.00
5/16"-18 3/4" 1 9/16" F 0.257" 4 UNC 1/4" 1021N12 30.00
3/8"-16 13/16" 1 19/32" 5/16" 0.3125" 4 UNC 1/4" 1021N13 40.00
Metric
Thread
Drill Bit
Plug Chamfer
Size Pitch,
mm Lg. Overall
Lg. Size Decimal Size
Equivalent No. of
Flutes Hex Shank
Size Each
Uncoated High-Speed Steel
M3 0.5 7/16" 1 5/16" 2.5 mm 0.0984" 3 1/4" 1021N21 $12.80
M3.5 0.6 3/8" 1 5/16" 2.9 mm 0.1142" 3 1/4" 1021N22 12.65
M4 0.7 1/2" 1 3/8" 3.3 mm 0.1299" 3 1/4" 1021N23 12.00
M5 0.8 5/8" 1 7/16" 4.2 mm 0.1653" 3 1/4" 1021N24 16.00
M6 0.75 11/16" 1 15/32" 5.2 mm 0.2047" 3 1/4" 1021N26 18.00
M6 1 11/16" 1 9/16" 5 mm 0.1968" 3 1/4" 1021N25 15.00
M7 1 5/8" 1 1/2" 6 mm 0.2362" 3 1/4" 1021N27 20.00
M8 0.75 3/4" 1 9/16" 7.2 mm 0.2834" 4 1/4" 1021N29 23.33
M8 1.25 3/4" 1 9/16" 6.7 mm 0.2637" 4 1/4" 1021N28 22.00
M10 1 13/16" 1 5/8" 8.9 mm 0.3503" 4 1/4" 1021N32 33.00
M10 1.5 13/16" 1 5/8" 8.5 mm 0.3346" 4 1/4" 1021N31 24.00
