The parts of a telescopic gauge include telescopic rods, internal spring, handle and locking screw. Read our full guide to the parts of a telescopic gauge rod!
Locking screw
The locking screw, at the bottom of the telescopic gauge, governs the movement of the telescopic rods. When the locking screw is turned anticlockwise it releases the spring attached to the rods so that they can move around freely.
When the locking screw is turned clockwise, the rods are locked in position, allowing the user to accurately measure the telescopic rods with a micrometre or vernier calliper.
Telescopic rods
Telescopic rods are the parts which measure the diameter of a bore.There is a telescopic rod on either side of the head on a telescopic gauge. The rods are attached to a spring which enables them to move in and out of their casing.
The ends of the telescopic rods are in the shape of a half ball, known as a radius edge, to allow them to measure the surface of a bore more accurately.
Internal Spring
The internal spring is attached to the telescopic rods and the locking screw. This is the part of the telescopic gauge which enables the telescopic rods to move.
Handle
The handle is made with added ridges, known as a knurl, on the outside to provide added grip. The handle can be either 60mm (2.4″), 203mm (8″), or 305mm (12″) in length.