THREADING SYSTEMS - JEL - 05/2008 - Komet

Tap drill diameters for milled and cut threads
NPT/NPTF
without using a reamer
Size
Pitch t.p.i.
Tap drill Ø Tap drill Ø
NPT NPTF
1/16 27 6,15 6,10
1/8 27 8,50 8,45
1/4 18 11,00 10,90
3/8 18 14,50 14,30
1/2 14 17,85 17,60
3/4 14 23,20 23,00
1“ 11 1/2 29,00 28,75
1 1/4“ 11 1/2 37,80 37,50
1 1/2“ 11 1/2 44,00 43,75
2“ 11 1/2 56,00 55,75
RC
without using a reamer
Size Pitch t.p.i. Tap drill Ø
RC 1/16 28 6,20
RC 1/8 28 8,20
RP 1/4 19 11,00
RC 3/8 19 14,50
RC 1/2 14 18,00
RC 3/4 14 23,50
RC 1“ 11 29,50
RC 1 1/4“ 11 38,25
RC 1 1/2“ 11 44,25
RC 2“ 11 55,75
RC 2 1/2“ 11 71,25
RC 3“ 11 83,75
EG
Helical Wire Insert Thread
Size Nom. Ø Pitch Tap drill Ø
EG M 3 3 0,50 3,15
EG M 3,5 3,5 0,60 3,70
EG M 4 4 0,70 4,20
EG M 4,5 4,5 0,75 4,75
EG M 5 5 0,80 5,25
EG M 6 6 1,00 6,30
EG M 7 7 1,00 7,30
EG M 8 8 1,25 8,40
EG M10 10 1,50 10,50
EG M12 12 1,75 12,50
EG M14 14 2,00 14,50
EG M16 16 2,00 16,50
EG M18 18 2,50 18,75
EG M20 20 2,50 20,75
EG M22 22 2,50 22,75
EG M24 24 3,00 24,75
EG M27 27 3,00 27,75
EG M30 30 3,50 31,00
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