GSG Thread Rings

A thread ring GO gage checks the maximum minor diameter and the maximum pitch diameter size in a part. The NOGO checks for the part not to exceed the minimum pitch diameter size on a part.

All GSG thread ring gages are manufactured to ASME/ANSI B1.2 or B1.16M. Each thread ring gage is made of oil-hardened tool steel.

Thread Ring Styles


  • Solid Thread Rings – The ISO standard used to set the zero systems variable ITC units.
  • AGD Thread Rings – Comply with ASME/ANSI B47.1 gage blank standard. Sizes below 1/4 (M6) are counterbored to hold a specific length.
  • Southern Style Rings – Set and stays round through all adjustments because of eccentric design and opposing pressures of the adjusting and locking mechanisms. Color-coded for easy identification of the GO and NOGO gage. The aluminum body makes large gage rings lightweight and easier to use. The GSG “Southern Style” thread ring features the unique “Automatic Helical Adjustment.” The Helix Path of the thread along the line of adjustment remains true and in alignment throughout the life of the gage.