Pipe Tap Drill Sizes

Pipe Tap Drill Sizes


TAPER
PIPE – NPT
  STRAIGHT
PIPE – NPS
TAP DRILL   TAP DRILL
SIZE SIZE   SIZE SIZE
1/8-27 R   1/8-27 S
1/4-18 7/16   1/4-18 29/64
3/8-18 37/64   3/8-18 19/32
1/2-14 23/32   1/2-14 47/64
3/4-14 59/64   3/4-14 15/16
1″-11-1/2 1-5/32   1″-11-1/2 1-3/16
1-1/4-11-1/2 1-1/2   1-1/4-11-1/2 1-33/64
1-1/2-11-1/2 1-47/64   1-1/2-11-1/2 1-3/4
2″-11-1/2 2-7/32   2″-11-1/2 2-7/3
2-1/2-8 2-5/8   2-1/2-8 2-21/32
3″-8 3-1/4   3″-8 3-9/32
3-1/2-8 3-3/4   3-1/2-8 3-25/32
4″-8 4-1/4   4″-8 4-9/32