Combi Gauge:
To control the thread tolerance the Leitech Combi gauge is used in the same way as any normal double-ended thread gauge.
As the Go end is inserted into the thread hole the measuring sleeve retracts into the aluminium body providing the user with an accurate depth reading.
The Not Go side is used is a conventional manner.
Scale=0.5mm resolution
Scale=.025" resolution
The Hi-resolution Thread Gauge:
is used in the same way as a Combi Gauge.
Also equipped with a locking device that allows the measuring sleeve to be locked at the depth reading.
The position of the thread hole to be measured is not always directly visible to the inspector and reading the scale is often difficult.
The locking device on the Hi-res Thread Gauge makes it possible to read the scale after the measurement has been taken.
Scale=0.1mm resolution
Scale=.005" resolution

Leitech 303958 Combi Hi-Resolution Go / No Go Thread Plug Gauge Size : 1/4 x 28 UNF 2B Depth : 1.000'' / 25mm