Default Re: New thread ring cannot be threaded onto truncated part of the master
Here is a question to go along with this thread.

I purchased new thread ring gages and new master set plugs. How come every time I receive a new thread ring it is so tight it cannot be threaded onto the truncated part of the master. I have double checked myself many times to make sure the master is correct. Any thoughts?
Dale, yes, I have two thoughts:
1. If the ring and set plug are for standard stocked sizes, it is totally possible that the two were not set together by the gage maker before they were shipped. The gage maker may have just pulled the two components from stock and shipped them. In that situation, the probability that the ring will fit the set plug is almost zero. The relationship between the ring gage and the set plug is a metal to metal fit. The set plug tolerance is 0.0003", or something similar, for a class X set plug. As you know, no two pieces are ever made to the same exact size. When you get standard ring gages, the gages are set to their in-house masters, which are most likely made to class W, and which is not the class X set plug that is pulled from the shelf as product. To fix this situation, request that the ring be set to the set plug by the gage maker before shipment. There may be a charge for this service on standard size gages.
2. If the gages have been set together, either by request or because you have ordered a special, before plate or oversize ring gage, you may experience a problem because the gage maker is determined to have a metal to metal fit. Their daily experience with this seems to build the muscles of the technician to the point where what he would call a light drag, you or I would call an interference fit. The amount of drag is variable depending on if you are Betty Boop, or Popeye on spinach.
Regardless of the reason, if the ring does not go on the set plug, reset the ring to fit your set plug if you feel compelled to do so. If the gage is certified, and you do not need it to fit your set plug at this time, use it as is and reset the ring at the first calibration.
Hope this answers your question.