The cylinder of the go-side shall be screwed into the thread without exerting force.
This is done over the complete length of the thread.
The no-go gauge of a screw limit plug gauge is marked with a red dot or a red stripe.
It shall be screwed into the thread as well without exerting force. During unscrewing, the number of turns are counted. If the number is higher than three, the thread is faulty.
The respective limit gauges can be found at each end of the screw limit plug gauge.