SCREW PLUG GAUGES
SCREW PLUG GAUGES
(OP)
Need to find out what the actual purpose of a screw plug gauge is. Namely is it used purely to measure a drilled and tapped hole, is it purely for screw (lathe) cut threads, cold rolled etc. Any info is very much appreciated.





RE: SCREW PLUG GAUGES
RE: SCREW PLUG GAUGES
Gages typically come in sets: Plug for box and ring for pin measurement. Typically a "GO" and "NOGO" plug/pin can provide the machinist with limits for acceptablility of threading. You need both to completely gage the thread.
Personally, I prefer the three wire measure, then use the pin to gage the box. This provides almost 83% accuracy and interchangability between box and pin threads in a manufactured at a fraction of the cost.
Kenneth J Hueston, PEng
Principal
Sturni-Hueston Engineering Inc
Edmonton, Alberta Canada