NPTF American Taper Pipe Thread
ANSI B 1.20.3

American Taper Pipe Thread for Dryseal joint without sealant compound. National Pipe Taper Fuel
The flank angle is 60°, the profile was originated by William Sellers.

Nominal Diameter	Major Diameter mm	Tapping Drill Size mm	TPI	Pitch mm
1/16" - 27 NPTF	7.870	6.00	27	0.940
1/8" - 27 NPTF	10.217	8.25	27	0.940
1/4" - 18 NPTF	13.577	10.70	18	1.411
3/8" - 18 NPTF	17.016	14.10	18	1.411
1/2" - 14 NPTF	21.211	17.40	14	1.814
3/4" - 14 NPTF	26.566	22.60	14	1.814
1" - 11 1/2 NPTF	33.195	28.50	11.5	2.209
1 1/4" - 11 1/2 NPTF	41.952	37.00	11.5	2.209
1 1/2" - 11 1/2 NPTF	48.021	43.50	11.5	2.209
2" - 11 1/2 NPTF	60.060	55.00	11.5	2.209
2 1/2" - 8 NPTF	72.642	65.50	8	3.175
4" - 8 NPTF	113.913	107.00	8	3.175
Advertising: