KEVOS® MAKEOS · Quality

Go and No-Go Gauge Sizes

What sizes should the go and no-go plug or ring gauges have for this toleranced feature?

Go and no-go gauge sizes for a hole (plug gauges) or shaft (ring or snap gauges) by Taylor’s principle, with gauge tolerance and wear allowance placed inside the work tolerance.

Open the calculatorRuns in your browser. No account needed.

How this tool works

Inputs, units and where to find them

InputUnitTypical source
FeaturechoiceHole or shaft.
Lower limit of sizemmSmallest permitted size from the drawing.
Upper limit of sizemmLargest permitted size from the drawing.
Gauge tolerance (% of work tolerance)%Gauge-maker’s tolerance as a share of the work tolerance (10% is a common rule; gauge standards set exact classes).
Wear allowance on go gauge (% of work tolerance)%Allowance on the go gauge for wear (0 if your system does not use one).

Method and formulas

  1. Work tolerance T = upper − lower; gauge tolerance G = % × T; wear W = % × T.
  2. Hole: go plug = lower + W to lower + W + G; no-go plug = upper − G to upper.
  3. Shaft: go ring = upper − W − G to upper − W; no-go ring = lower to lower + G.
  4. All gauge tolerances lie inside the work limits, so a good gauge never accepts a bad part.
  5. Example: a 25–25.021 mm hole needs a go plug of 25.0011 to 25.0031 mm and a no-go plug of 25.0189 to 25.021 mm.

Limitations

  • Inward (conservative) placement only; some standards allow other placements.
  • Gauge form, temperature and measuring force must also be controlled.
  • Example values are illustrations. Replace them with values for your actual task.

Typical uses

  • Specify limit gauges for production
  • Check a purchased gauge against the part limits
  • Decide gauge tolerance and wear allowance

Who it is for

  • Quality inspectors
  • Toolmakers
  • Metrology technicians

What you get

  • Go gauge size range
  • No-go gauge size range
  • Work tolerance used by the gauges

Interpreting the result

  • Calibrate gauges regularly and withdraw go gauges when worn past the low (or high) limit.

References

  • Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 661–663, 705–708. Topic reference; no source tables or recommended settings are reproduced.

WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.

Open the Go and No-Go Gauge Sizes calculator