Maintenance & Preservation of Gauges

2022-06-29

Maintenance & Preservation of Gauges

  • Gauge need to be thoroughly cleaned before and after use with either Alcohol or suitable solvent which do not contain water or leave an oil buildup.
  • Starrett M1 oil should be used when gauges are not in use. Do not use WD40 as it leaves a greasy buildup; really bad on gauge blocks.
  • The component must also be clean and free of metal particles.
  • Do not use thread gauges forcefully: like a tap or die.
  • Do not allow the gauge to be dropped on the shop floor, the gauges are brittle and may break.
  • Please note that the limit gauge is a precision tool and should be handled carefully.

Gauge Life

It is very difficult to predict gauge life. Gauges used against cast iron, aluminum and stainless/duplex steels have faster wear due to lapping effect of these material . However, gauge life can certainly be improved by proper use and care of the gauges as defined above. A calibration interval of one year to start and adjust after a history is established.

Troubleshooting

A working gauge answers/enters the components but the inspection gauge doesn't answer:
This is normally due to the size of the inspection go gauge slightly above the working go gauge. In such case the working gauge dimensions may be worn out or gauges are at either ends of the gauge tolerance. For future use, interchange the working and inspection gauges; and decrease your calibration interval.

Go gauge doesn't enter but the nogo answers freely:
This occurs due to major diameter of nut i.e. internal thread or minor diameter of bolt i.e. external thread is not maintained properly The major diameter of the go plug and minor diameter of the go ring gauge is sharp and hence obstructs with the corresponding diameter on the component. Hence the operator takes more material without correcting the tool sharpness. The nogo major diameter/minor diameter being more truncated than the go gauge, enters the component. The go gauge controls all the thread parameters and will not enter if any of these are incorrect. If there is no control on the actual point of error, the effective diameter of the component becomes oversized and the nogo gauge enters.