In Reply to Parent Post by Hershal
I recommend sending them out to an accredited lab for calibration.... Easier and cheaper to send them out,...
I agree with Hershal, unless you have a very complete in-house laboratory. Remember that these are in fact the masters for your ring gages.
That said, if the product manufactured in your facility is not safety critical, I see no reason that it can not be accomplished within your facility. The work of calibrating set plugs is little more than that of calibrating your working plugs.
- 3-wire measurements of the pitch diameter done at front, middle and back with the ultimate goal of the same size in all three places.
- Major diameter measurements of the full form major diameter. This is critical surface for determining the wear on the ring gage and is the first place you may see wear on your set plug gage.
- Truncated major diameter is not a wear surface and should not change from its original manufactured position. The specified tolerance on this feature is large by gage standards but could be larger without affecting the function of the setting plug. You (and some gage makers) don't really care if it is in tolerance or not as long as it is a little larger than the pitch diameter and much smaller than the full form major diameter.
NOTE: Tolerances on setting plugs
can be X or W. Basically W is half of X. When W is specified, usually only the pitch diameter is held to W. X-tolerance is the same tolerance used on working plugs. As a manufacturing plant I suggest that you work to X. If you were a commercial calibration laboratory there could be an argument made for using W, but it is still unnecessary in the grand scope of things.
I hope this has been helpful.