|Threaded body: Steel, blackened
Plunger pin: Steel, hardened and ground
Pull knob version: Matte black technopolymer
plastic (Polyamide PA), not removable
||GN 817.3 indexing plungers have been developed to enable precise locating when GN 770 guide bushes are used.
A plain guide bushing is used whereby the dimension l3 of the plunger determines the length of the bushing.
The precise location is, therefore, not dependent on the guide pin in the plunger, but on the accuracy of the guide bushing (bore tolerance G6) and the plunger (tolerance h7). Both components are hardened and ground. Of course, the bushing length also influences the accuracy of the positioning.
The version with rest position 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.