Threaded body: Steel, blackened
Plunger pin: Steel, hardened and ground
Knob: Matte black technopolymer
plastic (Polyamide PA), not removable
Type B - Non lock-out type, with plastic knob
Type C - Lock-out type
GN 817.5 indexing plungers make highly accurate positioning possible, by utilizing GN 172 / GN 179 drill bushings as a guide. The utilization of the drill bushing and either the GN 172.1 or GN 179.1 guide bushing provides two mating parts for the indexing plunger pin.
The conical shape of the indexing pin / indexing bore makes positioning virtually clearance-free and therefore highly precise.
The lock-out type is used in such applications where the plunger must not protrude continually. In that case, the knob is retracted and then turned by 90°. A notch prevents the plunger from turning by error or vibration.