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Reversible Trilock Thread Plug Gages

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Reversible Trilock Thread Plug Gages

  • Checks size of internal threads to ensure the they are within designed tolerance limits
  • Reversible gage members provides two gages for the price of one
  • Best suited for large size thread plug gages, 1 1/2 inches and larger
  • Class X Tolerance
  • GO and/or NO GO plug members
  • ASME/ANSI B1. 2 compliant
  • Chip groove provided on the Go member for ease of identification and clearing obstructions
  • Precision hand lapped to provide optimum finish and superior accuracy
  • Manufactured to the high end of the ANSI specifications to provide maximum wearability
  • Final inspection of gages is completed in an environmentally controlled ISO 17025 laboratory
  • Available in steel and chrome
  • Free NIST certificate of accuracy

Standard Pitch Diameter Chart - Inch



Standard Pitch Diameter Chart - Metric





Steel Chrome
Size Member Item # Price Item # Price
1 5/8-12 GO / NOGORTLS-01CallRTLC-01Call
DOUBLE ENDRTLSDE-01CallRTLCDE-01Call
1 5/8-16 GO / NOGORTLS-02CallRTLC-02Call
DOUBLE ENDRTLSDE-02CallRTLCDE-02Call
1 3/4-12 GO / NOGORTLS-03CallRTLC-03Call
DOUBLE ENDRTLSDE-03CallRTLCDE-03Call
1 3/4-16 GO / NOGORTLS-04CallRTLC-04Call
DOUBLE ENDRTLSDE-04CallRTLCDE-04Call
1 7/8-12 GO / NOGORTLS-05CallRTLC-05Call
DOUBLE ENDRTLSDE-05CallRTLCDE-05Call
1 7/8-16 GO / NOGORTLS-06CallRTLC-06Call
DOUBLE ENDRTLSDE-06CallRTLCDE-06Call
2-12 GO / NOGORTLS-07CallRTLC-07Call
DOUBLE ENDRTLSDE-07CallRTLCDE-07Call
2-16 GO / NOGORTLS-08CallRTLC-08Call
DOUBLE ENDRTLSDE-08CallRTLCDE-08Call
2 1/4-12 GO / NOGORTLS-09CallRTLC-09Call
DOUBLE ENDRTLSDE-09CallRTLCDE-09Call
2 1/4-16 GO / NOGORTLS-10CallRTLC-10Call
DOUBLE ENDRTLSDE-10CallRTLCDE-10Call
2 1/2-12 GO / NOGORTLS-11CallRTLC-11Call
DOUBLE ENDRTLSDE-11CallRTLCDE-11Call
2 1/2-16 GO / NOGORTLS-12CallRTLC-12Call
DOUBLE ENDRTLSDE-12CallRTLCDE-12Call
2 3/4-12 GO / NOGORTLS-13CallRTLC-13Call
DOUBLE ENDRTLSDE-13CallRTLCDE-13Call
2 3/4-16 GO / NOGORTLS-14CallRTLC-14Call
DOUBLE ENDRTLSDE-14CallRTLCDE-14Call
3-12 GO / NOGORTLS-15CallRTLC-15Call
DOUBLE ENDRTLSDE-15CallRTLCDE-15Call
3-16 GO / NOGORTLS-16CallRTLC-16Call
DOUBLE ENDRTLSDE-16CallRTLCDE-16Call


Reversible trilock thread plug gages are used to check the size of internal threads to ensure the threads are within its designed tolerance limits. The reversible trilock plug gage design is best suited for large size thread plug gages (1-1/2 inches and up), but is available in sizes as small as 3/4 inch. Consisting of a GO and/or NOGO member(s), the trilock has a bolt fastening system to support the size and weight. A chip groove is provided on the Go member for ease of identification and clearing obstructions.

Reversible trilock thread plug gages are manufactured in Class X tolerance and made in full conformance to ASME/ANSI B1.2 . Reversible trilock thread plugs can also be reversed on the handle resulting in a longer wear life. Gages ¾” (19.05mm) up to and including 1 ½” (38.1mm) are always assumed taperlock design unless Trilock reversible thread gage is specified when ordered.. WESTport thread plug gages are manufactured to the highest end of the ANSI specifications to ensure the longest gage life possible. Reversible trilock thread plug gages are available in steel and chrome.

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