Successful operation of manufacturing plants, where high accuracy is required, depends on measuring operations efficiency. An external gauge is a special measuring tool for precise measuring of linear dimensions and outer diameters of cylindrical parts. There are six standard sizes of external gauges with the measuring range from 0 to 150 mm. External gauges are equipped with heat-insulating covering plates, an arresting stop for the adjustable heel, and indicators of dimensional limits. Optionally, in addition to external gauges, a device for control of the angle diameter of the thread (by three-wire thread measurement method) with the measuring range up to 50 mm may be manufactured.
Measuring surfaces of external gauges are equipped with adjustable heels, which increase the measurement range, which allows for enterprise’s cost reduction, as less funds are required for instrumentation purchase. In addition to external measuring gauges and external control gauges, there are also caliper gauges. A caliper gauge is used for the control of the internal diameter of the workpiece (a shaft, a bushing, etc.). Unified requirements towards production process and operating rules for external gauges are specified in GOST 2216-84 and other reference documents.
| Name | Parameter | From | To | external gauge according to GOST |
|---|---|---|---|---|
| Sheet single-end external gauges | length (mm) | 10,5 | 360 | 18355-73 |
| Sheet double-end external gauges | length (mm) | 10,5 | 360 | 18356-73 |
| No-go external gauges for the control of the internal diameter of spline shafts with straight-sided profile during centering according to D | number of teeth (z) | 6 | 20 | 24964-81 |
| No-go external gauges for the control of the internal diameter of spline shafts with straight-sided profile during centering according to D | diameter (mm) | 11 | 112 | 24965-81 |
| Double-end external gauges for the control of the teeth thickness of spline shafts with straight-sided profile | thickness (mm) | 2,5 | 18 | 24966-81 |