How to use NoGo thread plug gage?
How to use NoGo thread plug gage?
(OP)
I would like to know the proper use of NoGo thread plug gages. My customer contacts aren't around today so I can't get the standard from them, it's not on the print, and I don't have it. That's some important information I need obviously.
The production manager believes the part can make up to 2 turns max onto the NoGo side and still be good. I don't buy it since the part only has 3 complete threads. (1.5 mm pitch)
The production manager believes the part can make up to 2 turns max onto the NoGo side and still be good. I don't buy it since the part only has 3 complete threads. (1.5 mm pitch)





RE: How to use NoGo thread plug gage?
RE: How to use NoGo thread plug gage?
There's no drag on the go side at all. I'm having the gage checked for wear.
RE: How to use NoGo thread plug gage?
RE: How to use NoGo thread plug gage?
Mike Halloran
Pembroke Pines, FL, USA
RE: How to use NoGo thread plug gage?
FED-STD-H28/6 paragraph 3.1.1:
Threads are acceptable when the HI thread plug gage is applied to the product internal thread if: (a) it does not enter, or if (b) all complete internal product threads can be entered, provided that a definite drag from contact with the product material results on or before the third turn of entry.
I would say it can go all three turns provided the gage doesn't bottom out in the hole and there is definite drag on the third turn.
JR97
RE: How to use NoGo thread plug gage?
ANSI/ASME B1.2 paragraph 4.2.1 says
"NOT GO (HI) functional diameter is acceptable when the NOT GO (HI) thread plug gage applied to the product internal thread does not enter more than three complete turns. The gage should not be forced. Special requirements such as exceptionally thin or ductile material, small number of threads, etc., may nececssitate modification of this practice."
Not much help in this particular case, but there it is