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HSS Npt Tap

Selected High Speed Steel NPT Bottom TapHSS NPT Tap
High Speed Steel NPT Bottom TapHSS 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.

Products

Dimensional Specifications

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