The ends are hardened and accurately finished by grinding. One end is the GO end and the other end is NOGO end.
· The ends are hardened and accurately finished by grinding. One end is the GO end and the other end is NOGO end.
· Usually, the GO end will be equal to the lower limit size of the hole and the NOGO end will be equal to the upper limit size of the hole.
· If the size of the hole is within the limits, the GO end should go inside the hole and NOGO end should not go.
· If the GO end and does not go, the hole is under size and also if NOGO end goes, the hole is over size. Hence, the components are rejected in both the cases.
1. Double ended plug gauges
In this type, the GO end and NOGO end are arranged on both the ends of the plug. This type has the advantage of easy handling.
2. Progressive type of plug gauges
In this type both the GO end and NOGO end are arranged in the same side of the plug. We can use the plug gauge ends progressively one after the other while checking the hole. It saves time. Generally, the GO end is made larger than the NOGO end in plug gauges.