Q: What is a thread plug gauge?
A: A thread plug gauge is a measuring tool consisting of two parts: a go plug gauge and a no-go plug gauge. It is used for a quick inspection to determine if a finished internal thread is within the specified tolerances.
Q: Why does it have a go and a no-go end?
A: The go end (the minimum tolerance gauge) checks if the thread is not too small. The no-go end (the maximum tolerance gauge) checks if the thread is not too large. The thread only meets specifications if both checks are successful.
Q: Why is the no-go end marked in red?
A: The red marking serves for quick visual differentiation. It helps to avoid confusion and to immediately recognize the no-go end, as its application differs from the go end.
Q: What does the reference temperature of 20° Celsius mean?
A: The 20°C reference temperature is the standard at which all threads and gauges are calibrated and tested. Temperature differences can cause the material to expand or contract, which would distort the measurement result.
Q: What are the consequences if a thread is scrap?
A: A scrap thread is not suitable for its intended use. It could cause the screw to not fit properly, come loose prematurely, or make the connection unstable. Such parts must be reworked or discarded.
