GO and NO-GO gauges for checking holes and shafts quickly in production.
In mass production every part cannot be measured with a micrometer. Limit gauges quickly check whether the size is within the limits. They do not show the actual size – only accept or reject.
GO and NO-GO
- GO side must enter (or pass over) the part.
- NO-GO side must not enter (or pass over).
- If GO goes and NO-GO does not go → the part is correct.
Types
| Gauge | Checks | Details |
|---|---|---|
| Plug gauge | Holes (bores) | GO end = lower limit of hole (longer), NO-GO end = upper limit (shorter, often marked red) |
| Ring gauge | Shafts (outside diameter) | Separate GO and NO-GO rings; NO-GO ring has a groove on its outside |
| Snap gauge | Shafts and thickness | C-shaped; GO jaw at front (upper limit), NO-GO jaw behind (lower limit) |
| Thread gauges | Threads | Thread plug and thread ring gauges |
Remember For a hole the GO size is the smallest allowed size; for a shaft the GO size is the largest allowed size.
Quick Revision
- Limit gauges accept or reject – they do not measure.
- Plug gauge → hole; ring and snap gauge → shaft.
- GO must go, NO-GO must not go.
Your progress is saved on this device.