Under uniform spring tension, the plunger of the gage expand from the center to the diameter of the hole or width of slot being measured and then locked in place by a knurled knob, the hole size is found by measuring over the two contact point with a micrometer or caliper.
Letter Code
Range
Overall Length
A
5/16" - 1/2" (8 mm to 12.7mm)
12"
Double action rigid handle with self centering feature for quick checking of holes, slots and recess up to 6" deep
The ends of both contact are heat treated stainless steel and precision ground to a radius to allow proper clearance on the smallest hole the gage will enter
Constant spring tension gives uniform contact pressure
Handles are rigidly attached to the contact plungers and are automatically self-centering