Functional Thread Size Gages

Functional thread size gages inspect the effects of all thread element variations and report deviations (functional size). The Functional thread size gages must be preset to a nominal predetermined dimension using either gage blocks, micrometers, or Gagemaker’s MIC TRAC measurement center. The gages use matched sets of precision ground thread rolls that seat in the threads during inspection to ensure accuracy. Each set of thread rolls is designed to ANSI specifications to measure unlimited diameters for a specific thread form. Common pitches ranging from 4 TPI to 20 TPI of the UN Series, ACME, and Stub ACME, and 1.5mm to 4 mm of the ISO Metric thread rolls are in stock. Whitworth and 7° X 45° Buttress thread rolls are available with a fast lead time.

The PG-6000 Series gages inspect diameters of internal threads. The RG-7000 Series gages measure diameters of external threads.

Special thread forms are priced upon request. All thread rolls are sold separately in matching sets.


  • Measures internal or external threads for a range of diameters
  • Uses interchangeable thread rolls for measurement of different thread forms.
  • Replaces conventional ring and plug gages by providing actual diameter readings.
  • Provides functional measurement by inspecting the effects of thread element variations such as: lead, taper, thread height and pitch diameter.
  • Eliminates unnecessary damage to threads caused by ring and plug gages.
  • Durable construction allows use in a manufacturing or field environment.
  • Requires presetting using basic gage blocks, micrometers, or Gagemaker’s MIC TRAC measurement center.

Functional Thread Size Gages View Data Sheet

  • Functional Thread Size Gages
    External Functional Gage (RG-7000)
  • Functional Thread Size Gages
    RG-7000 on part
  • Functional Thread Size Gages
    Internal Functional Gage (PG-6000)
  • Functional Thread Size Gages
    PG-6000 in part