PLUG GAUGES
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.
TAPER PLUG GAUGE
Taper
plug gauges are used to check tapered holes. It has two check lines. One is a
GO line and another is a NOGO line. During the checking of work, NOGO line
remains outside the hole and GO line remains inside the hole.
They
are various types taper plug gauges are available as shown in fig. Such as
1)
Taper plug gauge - plain
2)
Taper plug gauge - tanged.
3)
Taper ring gauge - plain
4)
Taper ring gauge - tanged.