In Reply to Parent Post by rnsvasan
Can anyone explain what are all the dimensions / parameters to be checked / ensured for ACME & LPT thread Plug & Ring gauge
The easiest way to get the specific dimensions you seek is to order Long Form Certifications with your new gages. The certifications will have all the required measurable data points identified with the associated tolerances; however; this does not give you official supporting documentation.
The official standards can be purchased from several outlets, and if you are calibrating the gages you should have a copy of the standard as your base reference document. One source of the documents is: Global Engineering Documents
For ACME search for B1.5
For NPT search for B1.20.1
The thread gage requirements can be generated by computer using ThreadTech Software. There is a free 10-day trial version
Calibrating ACME is fairly straight forward; use wires to check your plug gages and set plug gages to set your rings. Avoid using direct measurement on adjustable style ring gages like the plague. The methodology is fraught with hidden problems.
Calibrating NPT is best done with master gages. I recommend sending the masters out to a gage maker to be calibrated. Don't do them yourself.
Hope this helps some.