plug gauge

measurement instrument

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July 1, 2026

Quick Summary

A plug gauge is a measurement instrument used in manufacturing and engineering to determine if a hole's size is within a specified tolerance. It is a type of fixed-type gauge, meaning it indicates whether a dimension is larger or smaller than a standard.12

A plug gauge typically consists of a cylindrical bar with two ends of different diameters. The smaller end, marked "go," is designed to enter a hole if it is within the acceptable size range. The larger end, marked "not go," should not enter the hole if it is within tolerance. This "go" and "not go" system, also referred to as a go no-go gauge, ensures that manufactured parts meet precise specifications.23

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…hole, a cylindrical bar (plug gauge) with highly finished ends of different diameters is used. If the hole size is correct within tolerable limits, the small end (marked “go”) will enter the hole, while the large end (“not go”) will not. Ring gauges for checking the dimensions of cylindrical…
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…hole, a cylindrical bar (plug gauge) with highly finished ends of different diameters is used. If the hole size is correct within tolerable limits, the small end (marked “go”) will enter the hole, while the large end (“not go”) will not. Ring gauges for checking the dimensions of cylindrical…
Read More