Plug gauges

Plug gauges In the plain type, the go and not-go plugs often are fastened into the two ends of a single handle for convenience in use.In the step type, the go and not go diameter are on the a single plug, the go portion is the outer end.The not-go plug usually is much shorter than the go plug, it is subjected to little wear because it seldom slides into any holes.In using a plug or any other type of gauge, the gauge should never be forced into, or onto the part being measured.Plug gauge with stepped go and not-go member

GoNot-Go1

Plug gauges, typesThe common type of plug gauges are:Cylindrical shape plug gaugesPlain plug gaugeStep-type go, not go gaugeTaper plug gaugesFlat plug gaugesThread plug gauges2

Taper plug gaugesThere is a pair of marks etched at the proper pre-calibrated location.The tapered hole is too large if both marks on the gauge sink down out of sight.The tapered hole is too small if both marks are visible

Tapered plug gauges

Plug gauge to check a tapered hole3

Taper plug gaugesMethod for checking a tapered hole with a plug gauge. If first gauge mark enters hole, but second not, taper is correct.

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Flat plug gaugesThis gauge with go and not-go members designed to check the widths of slots, grooves, and channels.

(a) Flat plug gauge designed to check slots and channels(b) Example of keys, slots that can be checked using flat plug gauge.5