NPSM Straight Pipe Thread Ring Gages

NPSM straight pipe thread ring gages are manufactured per ANSI/ASME B1.20.1. NPSM threads are designed for free fitting mechanical joints. This pipe is often used for special applications where there is no internal pressures and is often found to be more suitable to use. All straight pipe thread ring gages are of Unified screw thread form and are supplied in a class 2A for external threads. The minimum pitch diameter of internal threads is basic and equal to E1 of NPT threads. Thread Check offers gages for a complete range for hose coupling screw threads covered under ASME B1.20.7. Other straight pipe thread gages include NPSF, NPSC, NPSL, NPSI, NPSH, and NH sizes. Thread Check’s expert sales engineers can assist you with selecting the correct gages for your application.

SKU Description Dec. Frac. TPI Pitch Diameter Each
NPSM-3.0-RG-GO 3.0"" - 8 NPSM 2A Go Thread Ring Gage - P.D. 3.3862" 3.0"383.3862"
NPSM-3.0-RG-NGO 3.0"" - 8 NPSM 2A No Go Thread Ring Gage - P.D. 3.3786" 3.0"383.3786"
NPSM-3.0-RG-SET 3.0"" - 8 NPSM 2A Go/No Go Thread Ring Gage Set 3.0"383.3862" - 3.3786"
Set Descending Direction
per page

Additional Info

Use thread setting plugs to calibrate and properly set adjustable thread ring gages. Adjustable Thread rings can only be calibrated by this method. Truncated thread setplugs have a thread with both a truncated and a full form thread for both the go and the no go member. The full form section inspects and sets the correct clearance and forms at the major diameter of the ring gage. The truncated section controls pitch diameter. A thread ring gage should be set on the full form portion of the setplug - the back portion. The ring is then turned onto the truncated portion and should have the same drag and fit as when turned through the full form. A ring gage which spins quickly through the truncated section or "shakes" usually indicates wear. The ring gage should be repaired by relapping if possible or replaced. See Technical Info Document - Calibration Procedures for Thread Ring Gages.

Thread Ring Gages

All Thread Check thread ring gages are root relieved for longer life and more accurate gaging. The gages are manufactured with a root clearance in the major diameter which eliminates the possibility of interference from the full form section of the thread setting plug and major diameter of the part being gaged. This feature assures that the thread flanks are making proper contact.

By clicking "I Agree", you agree to our Terms and that you have read our Data Use Policy.