Pg Conduit Thread Plug gages are used for checking threads of pipe fittings used for electrical wiring. The standard; DIN 40431 P2 Steel Conduit Thread, Thread Gauges, GO and NOGO specifies the requirements for these gages.
WESTport manufactures Pg Steel Conduit Thread Plug Gages compliant to the standard. The Pg thread series is designed specifically for the thin wall cross section of the steel conduit. The thin wall thickness requires a shorter profile thread that will not break through the outside diameter of the steel conduit during the machining process. The Pg conduit thread form features an 80° included angle and a shorter profile than the 60° included angle found in the Unified National thread series and the Metric thread series.
The DIN 40430 standard for P1 steel conduit threads specifies the requirements for using GO thread plug gages and plain NOGO plug gages to inspect the conduit threads. A unique aspect of the Pg Steel Conduit Thread Plug Gage is that the NOGO member is a plain cylindrical gage. This works because as the thread is machined the crest if the thread comes to a point. As the thread size is changed, the position of the point changes and as a result can be measured. The plain NOGO plug gage checks the minor diameter or crest of the thread and verifies that minimum material condition is met. The GO threaded plug works normally by ensuring the maximum material condition is met.
Pg Conduit thread plug gages are easy to use:
1. The GO threaded plug gage must be capable of being screwed by hand without undue force over the full length of the threaded work piece
2. The NOGO plain plug gage must not be able to pass over the threaded work piece