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API Thread Gages

Fixed and Ground Limit Gaging for Plug & Ring Thread Gages


PMC Lone Star is the leading manufacturer of fixed and ground limit gaging for both plug & ring thread gages. PMC Lone Star will meet your requirements and custom build your thread gages to meet your exact specifications. Our gage engineering team is ready to design and work with you on all your thread gaging needs.


API Gages,API Gauges PMC Lonestar is licensed by API to Spec Q1, Spec 5B, 7 & 11B and manufactures a complete line of API (American Petroleum Institute) plug and ring gages for:

  • Casing - sizes 4 ˝" - 20", both working & masters
  • Line Pipe - sizes 1/8" - 20D, both working & masters
  • Tubing - EUT 1.050 - 4 ˝", both working & masters, NUT 2 3/8" - 4 ˝", both working & masters
  • Buttress Casing - sizes 4 ˝" - 20", both working & masters
  • Improved Buttress Tubing - sizes 2" - 5 ˝", both working & masters
  • Sucker Rod - masters P1-P8 & B1-B6, working gages P2-P8 & B2-B6
  • Polished Sucker Rod
  • Numbered Connections - NC10-NC77, both working & masters
  • Regular Rotary Shoulder Connections- sizes 1" - 8 5/8", both working & masters
  • Full Hole - sizes 2 7/8" - 6 5/8", both working & masters
  • Internal Flush - sizes 2 3/8" - 5 ˝", both working & masters
  • Extreme Line Gages
  • Negative Flank Angle – we have recently introduced fixed and ground negative flank angle gages to our product line.

Field proven for over half a century, our master and working plug and ring thread gages meet and exceed specifications established by the American Petroleum Institute (A.P.I) and are used as the benchmark for calibration by the National Institute of Standards and Technology (NIST). PMC Lone Star designs and manufactures special oil country gages to your specifications.

Contact us for current gaging prices and availability.