HSS NPT Tap
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HSS NPT Tap

The nominal size of a High Speed Steel Taper Pipe Tap (NPT) is that of the pipe fitting to be tapped, not the actual size of the tap. They are for general use in production tapping or hand operations in a wide range of application material groups.

Dimensional SpecificationsHSS NPT Tap

Tap Size

Thread Overall
Length
Length of
Thread
Number
of Flutes
1/16 27 2 1/8 11/16 4
1/8 27 2 1/8 3/4 4
1/4 18 2 7/16 1 1/16 4
3/8 18 2 9/16 1 1/16 4
1/2 14 3 1/8 1 3/8 4
3/4 14 3 1/4 1 3/8 5
1 11 1/2 3 3/4 1 3/4 5
1 1/4 11 1/2 4 1 3/4 5
1 1/2 11 1/2 4 1/4 1 3/4 7
2 11 1/2 4 1/4 1 3/4 7
2 1/2 8 5 1/2 2 9/16 8
3 8 6 2 5/8 8
3 1/2 8 6 1/2 2 11/16 8
4 8 6 3/4 2 3/4 8
  1. All dimensions are in inches.

Tap Drill Chart

Tap Size Drill Size Probable
% Thread
M3-0.5 40 70-79
5-40 38 65-72
5-44 37 63-71
M3.5-0.6 33 72-81
6-32 36 71-78
6-40 33 69-77
M4-0.7 3.25 mm 74-82
8-32 29 62-69
8-36 29 70-78
10-24 25 69-75
10-32 21 68-76
M5-0.8 4.2 mm 69-77
12-24 16 66-72
12-28 15 70-78
M6-1.0 10 76-84
1/4-20 7 70-75
1/4-28 3 72-80
5/16-18 F 72-77
5/16-24 I 67-75
M8-1.25 6.7 mm 74-80
3/8-16 5/16 72-77
3/8-24 Q 71-79
M10-1.50 8.4 mm 76-82
7/16-14 U 70-75
7/16-20 25/64 65-72
M12-1.75 13/32 69-74
1/2-13 27/64 73-78
1/2-20 29/64 65-72
Tap Size Drill Size Probable
% Thread
M14-2.0 15/32 76-81
9/16-12 31/64 68-72
9/16-18 33/64 58-65
5/8-11 17/32 75-79
5/8-18 37/64 58-65
M16-2.0 35/64 76-81
3/4-10 21/32 68-72
3/4-16 11/16 71-77
M20-2.5 11/16 74-78
7/8-9 49/64 72-76
7/8-14 13/16 62-67
M24-3.0 53/64 72-76
1-8 7/8 73-77
1-12 59/64 67-72
1-14 15/16 61-67
1-1/8-7 63/64 72-76
1-1/8-8 1 76
1-1/8-12 1-3/16 66-72
M30-3.5 1-3/64 75
1-1/4-7 1-7/64 76
1-1/4-8 1-1/8 76
1-1/4-12 1-11/64 72
1-3/8-6 1-7/32 72
1-3/8-12 1-19/64 72
M36-4.0 1-1/4 82
1-1/2-6 1-11/32 72
1-1/2-8 1-3/8 76
1-1/2-12 1-27/64 72
NPT Tap Size Taper Pipe
Drill Size
Straight Pipe
Drill Size
1/8-27 R 11/32
1/4-18 7/16 7/16
3/8-18 37/64 37/64
1/2-14 45/64 23/32
3/4-14 59/64 59/64
1-11.5 1-5/32 1-5/32
1-1/4-11.5 1-31/64 1-1/2
1-1/2-11.5 1-47/64 1-3/4
2-11.5 2-7/32 2-7/32
HSS NPT Tap
View
Size Thread Pitch Tap Type Item # Availability Price Quantity UOM
1/8 27 NPT TAPS012-NPT In Stock $35.37129/EA EA
1/4 18 NPT TAPS025-NPT In Stock $38.73911/EA EA
3/8 18 NPT TAPS037-NPT In Stock $43.33474/EA EA
1/2 14 NPT TAPS050-NPT In Stock $68.63739/EA EA
3/4 14 NPT TAPS075-NPT In Stock $95.2011/EA EA
1 12 NPT TAPS100-NPT In Stock $139.19861/EA EA
1 1/4 12 NPT TAPS125-NPT In Stock $199.24953/EA EA
1 1/2 12 NPT TAPS150-NPT In Stock $267.97998/EA EA
2 12 NPT TAPS200-NPT In Stock $364.60287/EA EA