Clamp Bolts for extremely accurate and repeatable re-clamping

Pilgrim Admin


The mission of the NATIONAL SOLAR OBSERVATORY (US) is to advance knowledge of the Sun, both as an astronomical object and as the dominant external influence on Earth, by providing forefront observational opportunities to the research community.

The mission includes the operation of cutting edge facilities, the continued development of advanced instrumentation both in-house and through partnerships, conducting solar research, and educational and public outreach.

In 2014 PILGRIM was contacted by ALL WORLD MACHINERY of Illinois (US) to design a bolting solution to connect the telescope mirror to the optic support structure for the customer NSO, who were building the Daniel K. Inouye Solar Telescope for the Haleakalā Observatory in Hawaii.


PILGRIM’S hydraulically installed Clamp Bolt sitting on self aligning spherical plates consisting of:

  • M64x6 x 480mm length bolts with steel ends caps with retained load of 908kN
  • 1 off Bolt tensioning kit
  • 1 off Morpress air driven hydraulic pump


  • Easy to install and remove
  • A bolt that can maintain the required clamping forces during operation, while keeping the self aligning functionality of the design.
  • Safe to install and remove