It is easy to use thread gages, including thread ring gage and plug gauges. First, the most important thing is to choose correct and suitable thread gages. The user should be clear Major diameter, TPI/pitch, Thread form, class of fit etc. For example, 1 1/2-8 UN 2A ring gage. 1 1/2″ is the diameter, 8 is the TPI, The thread form is United Inch, Class of fit is 2A. This 1 1/2-8 UN 2A ring gage is used to check external thread. The user should also care for the standard, for example, 1 1/2-8 UN 2A ring gage should confirm to Standard：ASME B1.2-1983.
Second:for some threaded parts which have special diameter requirements, then the thread gauges should be produced specially for suiting the requirements. For example, this week gaugestools received an order as below
Plug Gage for: 3.400- 4 ACME-4C RH(right hand)
Major Dia. = 3.4055/3.4018
Pitch Dia. = 3.2837/3.2750
Minor Dia. = 3.1875/3.1750
Ring Gage for: 3.400 – 4 ACME-4C LH(left hand)
Major Dia. = 3.4000/3.3980
Pitch Dia. = 3.2670/3.2583
Minor Dia. = 3.1300/3.1170
Ring Gage for: 3.400 – 4 ACME-4C RH
Major Dia. = 3.4000/3.3980
Pitch Dia. = 3.2670/3.2583
Minor Dia. = 3.1300/3.1170
Ring Gage for: 5.375 – 3 1/2 ACME-2G RH
Major Dia. = 5.3750/5.3607
Pitch Dia. = 5.2136/5.1836
Minor Dia. = 5.0693/5.0244
All our ACME thread gauges will be produced according to these diameter requirements.
Third, the user should be sure the thread gauges are calibrated. Usually, the calibration frequency is annual, but to some thread gauges which are frequently used, it need more time’s calibration in one year.
Fourth, Prior to gauging, the working parts should be cleaned, which will extend the thread gages’ using life. After gauging, the thread gages should be added a little anti-rust oil and kept well in tool boxes, pay much attention to the rain, moisture, sunshine and keep away from other objects.
Fifth, The GO end of the thread gages should go entirely to the end of working parts without using too much force, the NOGO end of the thread gauges should be stopped not exceeding three turns. Just in this case, we can judge the threads of working parts are qualified. Otherwise, we we judge the threads are not fine enough.
Date: 1th.Mar.2018
