MTS Series 646 Hydraulic Collet Grips - Manual (Page 61)

Series 646 Hydraulic Collet Grips Operation 61
6. Place the remaining collet retainer over the remaining threaded insert.
Ensure that the collet retainer is oriented so the side with the spanner holes
will be facing the upper grip.
7. Thread the threaded insert with the collet retainer onto the lower end of the
specimen until the same number of threads are left exposed as in Step 5
above.
8. Apply system hydraulic pressure to the load unit.
9. Extend the actuator until the collet retainer contacts the lower grip.
10. Insert a spanner wrench into the lower collet retainer and continue to extend
the actuator as far as possible (without allowing the spanner wrench to
contact the upper collet retainer), or until the specimen contacts the preload
platen.
11. Using the spanner wrench, thread the collet retainer into the lower grip. If
necessary, alternately continue to extend the actuator and thread the collet
retainer until the collet retainer is threaded fully into the grip housing.
Ensure that when the collet retainer is threaded fully into the grip housing
the alignment markings on the collet retainer and grip housing are aligned.
Screw the threaded insert onto or off of the specimen, as necessary, to
achieve proper alignment. However, ensure that the specimen maintains
contact with the preload platen. Lock the lower grip.