THREADING SYSTEMS - JEL - 05/2008 - Komet

Tap drill diameters for milled and cut threads
UNC
American Unified
Coarse Thread
UNF
American Unified
Fine Thread
Size Nom. Ø Pitch t.p.i. Tap drill Ø Size Nom. Ø Pitch t.p.i. Tap drill Ø
Nr. 4 2,845 40 2,35 Nr. 4 2,845 48 2,30
Nr. 5 3,175 40 2,65 Nr. 5 3,175 44 2,60
Nr. 6 3,505 32 2,85 Nr. 6 3,505 40 2,85
Nr. 8 4,166 32 3,50 Nr. 8 4,166 36 3,45
Nr. 10 4,820 24 3,90 Nr. 10 4,826 32 4,05
Nr. 12 5,486 24 4,50 Nr. 12 5,486 28 4,60
1/4 6,350 20 5,10 1/4 6,350 28 5,45
5/16 7,938 18 6,60 5/16 7,938 24 6,90
3/8 9,525 16 8,00 3/8 9,525 24 8,45
7/16 11,112 14 9,40 7/16 11,112 20 9,85
1/2 12,700 13 10,80 1/2 12,700 20 11,45
9/16 14,288 12 12,20 9/16 14,288 18 12,90
5/8 15,875 11 13,50 5/8 15,875 18 14,45
3/4 19,050 10 16,50 3/4 19,050 16 17,45
7/8 22,225 9 19,50 7/8 22,225 14 20,40
1“ 25,400 8 22,50 1“ 25,400 12 23,30
1 1/8“ 28,575 7 25,00 1 1/8“ 28,575 12 26,45
1 1/4“ 31,750 7 28,00 1 1/4“ 31,750 12 29,65
1 3/8“ 34,925 6 30,75 1 3/8“ 34,925 12 32,80
1 1/2“ 38,100 6 34,00 1 1/2“ 38,100 12 36,00
1 3/4“ 44,450 5 39,50
2“ 50,800 4 1/2 45,00
UNEF
American Unified
Extra Fine Thread
W
Whitworth Thread
Size Nom. Ø Pitch t.p.i. Tap drill Ø Size Nom. Ø Pitch t.p.i. Tap drill Ø
Nr. 12 5,486 32 4,75 1/8“ 3,175 40 2,60
1/4 6,350 32 5,55 3/16“ 4,762 24 3,60
5/16 7,938 32 7,15 1/4“ 6,350 20 5,10
3/8 9,525 32 8,70 5/16“ 7,938 18 6,50
7/16 11,112 28 10,20 3/8“ 9,525 16 7,90
1/2 12,700 28 11,80 7/16“ 11,113 14 9,25
9/16 14,288 24 13,20 1/2“ 12,700 12 10,50
5/8 15,875 24 14,80 5/8“ 15,876 11 13,50
11/16 17,462 24 16,40 3/4“ 19,051 10 16,50
3/4 19,050 20 17,80 7/8“ 22,226 9 19,25
13/16 20,637 20 19,40 1“ 25,401 8 22,00
7/8 22,225 20 20,95 1 1/8“ 28,576 7 24,75
15/16 23,812 20 22,50 1 1/4“ 31,751 7 27,75
1“ 25,400 20 24,15 1 3/8“ 34,926 6 30,50
1 1/16“ 26,987 18 25,60 1 1/2“ 38,101 6 33,50
1 1/8“ 28,575 18 27,20 1 5/8“ 41,277 5 35,50
1 3/16“ 30,162 18 28,75 1 3/4“ 44,452 5 39,00
1 1/4“ 31,750 18 30,35 1 7/8“ 47,627 41/2 41,50
1 5/16“ 33,337 18 31,95 2 50,802 41/2 44,50
1 3/8“ 34,925 18 33,50
1 7/16“ 36,512 18 35,10
1 1/2“ 38,100 18 36,70
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