Gage Calibration FAQs

What are gages used for?

Fixed limit gages are primarily used to check dimensions and geometries; plug gages check internal and ring gages external dimensions and geometries. They effectively insure that a part being measured is within its designed tolerance limits. Fixed limit gages are highly accurate, economical and easy to use.

What are the principles of Go/NoGo gaging?

To use as a "Go/NoGo" functional check, try and fit both the "Go" and "NoGo" gages into or onto a part being measured. The measured part passes if the "Go" gage fits and the "NoGo" doesn't, otherwise the part fails. A "Go/NoGo" check is strictly a pass/fail test. The actual part size is never measured.

What are the types of fixed limit gages?

Plug gages are available in two types’ plain cylindrical and thread, and in several popular styles: reversible, Taperlock, and Trilock. The style is usually determined by the size of the gage. Ring gages are also available as plain cylindrical and thread type gages.

What kinds of wear resistance and tolerance are there?

Gages are available in tool steel, chrome, and carbide. Chrome and carbide are harder and provide longer life to the gage. A choice of tolerance is also available. Please refer to the Gagemaker's tolerances chart to see which tolerance best suits your needs.

How is gage tolerance calculated?

The standard practice for determining gage tolerance is to allow 10% of the product tolerance to be divided between the "Go" and "NoGo" gages. For plug gages, the "Go" is normally a plus tolerance and "NoGo" a minus tolerance. For ring gages the opposite is true; "Go" is normally a minus tolerance and "NoGo" a plus tolerance. Using this practice as a guideline, gage tolerance is always included in the part tolerance and accounts for up to 10%. This means that 10% of good product could potentially fail the inspection but that no bad product would ever pass.

Is it cost effective to outsource my calibration?

Is gage calibration an investment in quality production?