NPT Threads

 

The NPT thread is a thread standard from America for a self-sealing pipe fitting. In practice, a sealant such as hemp or Teflon tape is placed between the threads of pipe fittings to ensure tightness. Only at low pressure is the thread self-sealing without sealant. The internal as well as the external thread have a conical thread form.

 

NPT Threads Chart

Thread

Sizes

Thread Pitch

(mm)

Outer Diameter

(mm)

Core Hole Diameter

(mm)

Gear number

pro Inch

 NPT 1/16" 0,941 7,90 6,00 27
 NPT 1/8" 0,941 10,24 8,25 27
 NPT 1/4" 1,411 13,62 11,00 18
 NPT 3/8"  1,411 17,06 14,50 18
 NPT 1/2"  1,814 21,22 17,75 14
 NPT 3/4"  1,814 26,57 23,00 14
 NPT 1"  2,209 33,23 29,00 11,5
 NPT 1 1/4"  2,209 41,99 37,50 11,5
 NPT 1 1/2"  2,209 48,05 44,00 11,5
 NPT 2"  2,209 60,09 56,00 11,5
 NPT 2 1/2"  3,175 72,70 66,50 8
 NPT 3"  3,175 88,61 82,50 8
 NPT 3 1/2"  3,175 101,32 94,50 8
 NPT 4"  3,175 113,97 107,00 8
 NPT 5"  3,175 141,30 134,50 8
 NPT 6"  3,175 168,28 161,00 8
 NPT 8"  3,175 219,08 221,50 8
 NPT 10"  3,175 273,05 265,50 8
 NPT 12"  3,175 323,85 315,79 8

* All information without guarantee.

Tip !

Pipe thread Sealing cord or sealing tape.