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Taperpipe Thread Ring Gages

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Taperpipe Thread Ring Gages

  • NPT L1 rings inspect the functional size or hand tight engagement of the pipe, nipple or male threads
  • NPTF L1 ring gages inspect the functional size or hand tight engagement of the pipe, nipple or male threads
  • NPTF L2 ring inspects the wrench engagement threads of a coupling and taper of the external threads and to be used in conjunction or relationship with the NPTF L1
  • NPTF 6 step ring gages check the crest truncation or profile of the external threads and are used in conjunction or relationship with the L1 ring
  • NPT pipe thread plug and ring gages are manufactured per ANSI/ASME B1.20.1
  • NPTF gages are manufactured per ANSI/ASME B1.20.5
  • Free NIST certificate

National Standard Taperpipe Threads NPT Chart




Part# Product Name Size Price Sale Price
NPTR-01 Taperpipe NPT Ring L-1 1/16-27 $174.00 $158.00
NPTR-02 Taperpipe NPT Ring L-1 1/8-27 $132.00 $120.00
NPTR-03 Taperpipe NPT Ring L-1 1/4-18 $132.00 $120.00
NPTR-04 Taperpipe NPT Ring L-1 3/8-18 $142.00 $128.00
NPTR-05 Taperpipe NPT Ring L-1 1/2-14 $159.00 $143.00
NPTR-06 Taperpipe NPT Ring L-1 3/4-14 $180.00 $162.00
NPTR-07 Taperpipe NPT Ring L-1 1-11 1/2 $205.00 $185.00
NPTR-08 Taperpipe NPT Ring L-1 1 1/4-11 1/2 $226.00 $204.00
NPTR-09 Taperpipe NPT Ring L-1 1 1/2-11 1/2 $268.00 $242.00
NPTR-10 Taperpipe NPT Ring L-1 2-11 1/2 $319.00 $289.00
NPTR-11 Taperpipe NPT Ring L-1 2 1/2-8 $375.00 $339.00
NPTR-12 Taperpipe NPT Ring L-1 3-8 $471.00 $427.00
NPTR-13 Taperpipe NPT Ring L-1 3 1/2-8 $644.00 $582.00
NPTR-14 Taperpipe NPT Ring L-1 4-8 $735.00 $665.00
NPTR-15 Taperpipe NPT Ring L-1 5-8 $888.00 $804.00
NPTR-16 Taperpipe NPT Ring L-1 6-8 $1,048.00 $948.00


NPT L1 taper pipe ring gages are used to check external threaded parts.

NPT L1 rings inspect the functional size or hand tight engagement of the pipe, nipple or male threads. When gaging NPT threaded parts, thread the marked side on first. Parts being checked are generally acceptable when they come flush to end of ring to plus (+) or minus (-) one turn.

NPTF L1 ring gages are used to check external threaded parts. NPTF L1 ring gages inspect the functional size or hand tight engagement of the pipe, nipple or male threads. NPTF gages are used to inspect pipe threads that are used in Dryseal applications NPTF (Dryseal) and ANPT (Aeronautical) thread tolerances are more closely controlled requiring an L2 thick ring gage as well as the L1 ring.

NPTF L2 ring inspects the wrench engagement threads of a coupling and taper of the external threads and to be used in conjunction or relationship with the NPTF L1. NPTF gages are used to inspect pipe threads that are used in Dryseal applications NPTF (Dryseal) and ANPT (Aeronautical) thread tolerances are more closely controlled requiring an L2 thick ring gage as well as the L1 ring.

NPTF 6 step ring gages are used to check external threaded parts. NPTF 6 step ring gages check the crest truncation or profile of the external threads and are used in conjunction or relationship with the L1 ring. NPTF gages are used to inspect pipe threads that are used in Dryseal applications NPTF (Dryseal) and ANPT (Aeronautical) thread tolerances are more closely controlled requiring an L2 thick ring gage as well as the L1 ring.

NPTF gages are used to inspect pipe threads that are used in dryseal applications. NPTF gages are manufactured per ANSI/ASME B1.20.5. Standard practice for gaging NPTF threads calls for using 2 or 3 gages used in conjunction with each other. The standard calls out class 1 and class 2 NPTF threads. Class 1 signifies that specific inspection of root and crest truncation is not required, while class 2 signifies that such is required. Other taper pipe thread gages include PTF SAE Short and NGT sizes.

WESTport Gage offers a complete line of taper pipe gages including special and custom designs. NPT general purpose pipe thread plug and ring gages are manufactured per ANSI/ASME B1.20.1. Threads are within the permissible limits of the tolerance when the gaging notch of the plug or gaging face of the ring is plus or minus one turn from being flush with the end of the thread.

WESTport Manufactured Products. 24th Anniversary Servicing Industry Worldwide (1989-2013)