Someone maybe want to know after how many uses, their thread gages are possible to be worn out, they should send thread gauges to calibration lab for calibration. For example the standard UN thread gauges, ACME thread gauges, Metric thread gages, NPT thread gages etc, is there appropriate amount of uses for each kind of gage? It is better to have a clear guideline for calibration interval and amount of uses.
First, I should say it is a pretty complicated question. because there are many factors will affect the using of thread gages. For example, material gages used in, (brass, steel, stainless steel?) of course, using on stainless steel, it is easier to be worn out. Different user, some users are experienced, and know exactly how to use these thread gages, and they know to light touch thread gage, not using too big “force”, another kind of user, who don’t know how to use thread gages, they use them in wrong way, and they like to force the gages, of course, if in this way, the thread gages are likely to be worn out easier. In addition, condition of hole, dry, enough of lubrication,clean or off center, all these affect the gage using. But thread gages are usually made from oil hardened tool steel, they have hardness of 58-62 HRC, Usually they can last for a long time, as long as you know not to use too much force, and never use pipe wrench to torque them. the usual calibration interval is 12 months-one year. After one year using, it is better user send the thread gages to calibration lab to check whether the gages have any damage.
Second, different tolerance requirements leads to different uses before calibration. there are some threaded goods which are no accurate, just ” make is work” is okey, the thread class is 1B, 2B. of course, you can use too many uses, and the calibration interval is one year or two year , all are okey. if you can producing aerospace parts, or defense parts with tolerances of .0005 or less, for example, 1/2-20 UNF 3A ring gage. you can take more care of these high precision thread gages, you should use light touch, many after 1-2 months using, you need to send to the calibration lab to have a calibration.
Conclusion: how many uses before calibration, it is really no certain answers, it depends on different conditions. Many factors affect it.