Specifications of International Thread Standards

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 DiameterMajor Diameter
mm
Tapping
Drill Size
mm
TPIPitch
mm
1/16" - 27 NPTF7.8706.00270.940
1/8" - 27 NPTF10.2178.25270.940
1/4" - 18 NPTF13.57710.70181.411
3/8" - 18 NPTF17.01614.10181.411
1/2" - 14 NPTF21.21117.40141.814
3/4" - 14 NPTF26.56622.60141.814
1" - 11 1/2 NPTF33.19528.5011.52.209
1 1/4" - 11 1/2 NPTF41.95237.0011.52.209
1 1/2" - 11 1/2 NPTF48.02143.5011.52.209
2" - 11 1/2 NPTF60.06055.0011.52.209
2 1/2" - 8 NPTF72.64265.5083.175
4" - 8 NPTF113.913107.0083.175
NPTF