Page 725 - Iscar

USER GUIDE
TAPS

Pre-Tapping Hole Sizes - Forming Taps Pre-Tapping Hole Sizes - General Taps

Recommended Recommended American Unified American Unified
Tap Drill Size Tap Drill Size Coarse Threads Fine Threads
Drill
Drill
M Pitch Size MF Pitch Size UNC T.P.I Max. Size UNF T.P.I Max. Drill
Drill
mm
mm
Core
Core
mm
mm
Size
Dia.
1 0.25 0.9 2.5 0.35 2.37 inch mm Dia. mm
1.1 0.25 1 2.6 0.35 2.47 inch
1.2 0.25 1.1 3 0.35 2.88 #1 64 1.585 1.5 #0 80 1.306 1.3
1.4 0.3 1.28 3.5 0.35 3.38 #2 56 1.872 1.8 #1 72 1.613 1.6
1.6 0.35 1.47 4 0.5 3.8 #3 48 2.146 2.1 #2 64 1.913 1.9
1.7 0.35 1.57 5 0.5 4.8
1.8 0.35 1.67 6 0.5 5.8 #4 40 2.385 2.3 #3 56 2.197 2.1
2 0.4 1.85 6 0.75 5.7 #5 40 2.697 2.6 #4 48 2.459 2.4
2.2 0.45 2.03 7 0.75 6.7 #6 32 2.896 2.85 #5 44 2.741 2.7
2.3 0.4 2.15 8 0.75 7.7
2.5 0.45 2.33 8 1 7.6 #8 32 3.528 3.5 #6 40 3.012 3
2.6 0.45 2.43 9 0.75 8.7 #10 24 3.95 3.9 #8 36 3.597 3.5
3 0.5 2.8 9 1 8.6 #12 24 4.59 4.5 #10 32 4.168 4.1
3.5 0.6 3.25 10 0.75 9.7 1/4" 20 5.25 5.2 #12 28 4.717 4.7
4 0.7 3.7 10 1 9.6
4.5 0.75 4.2 10 1.25 9.45 5/16" 18 6.68 6.6 1/4" 28 5.563 5.5
5 0.8 4.65 11 1 10.6 3/8" 16 8.082 8 5/16" 24 6.995 6.9
6 1 5.1 12 1 11.6 7/16" 14 9.441 9.4 3/8" 24 8.565 8.5
7 1 5.6 12 1.25 11.45
8 1.25 6.6 12 1.5 11.35 1/2" 13 10.881 10.75 7/16" 20 9.947 9.9
9 1.25 7.45 14 1 13.6 9/16" 12 12.301 12.25 1/2" 20 11.524 11.5
10 1.5 8.45 14 1.25 13.45 5/8" 11 13.693 13.5 9/16" 18 12.969 12.9
11 1.5 9.35 14 1.5 13.35 3/4" 10 16.624 16.5 5/8" 18 14.554 14.5
12 1.75 11.25 15 1 14.6
14 2 13.1 15 1.5 14.35 7/8" 9 19.52 19.5 3/4" 16 17.546 17.5
16 2 15.1 16 1 15.6 1" 8 22.344 22.25 7/8" 14 20.493 20.5
18 2.5 16.85 16 1.5 15.35 1*1/8" 7 25.082 25 1" 12 23.363 23.25
20 2.5 18.85 18 4 17.6
22 2.5 20.85 18 1.5 17.35 1*1/4" 7 28.258 28.25 1*1/8" 12 26.538 26.5
24 3 22.65 18 2 17.1 1*3/8" 6 30.851 30.75 1*1/4" 12 29.713 29.5
27 3 25.65 20 1 19.6 1*1/2" 6 34.026 34 1*3/8" 12 32.888 32.7
30 3.5 28.4 20 1.5 19.35 1*3/4" 5 39.56 39.5 1*1/2" 12 36.063 36
33 3.5 31.4 20 2 19.1
36 4 34.15 24 2 23.1 2" 4.5 45.367 45.25
39 4 37.15 30 2 29.1
42 4.5 39.9 36 3 34.65
45 4.5 42.9 42 4 40.15
48 5 45.65 48 3 46.65

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