Thru-Bolt Installations

Thru-Bolt Installations

Installations where “thru-bolts” are used to make UNISTRUT® connections require special torque considerations compared to channel nut torque requirements.  Unlike channel nut attachments, “thru-bolts” induce a compressive load into the channel sidewalls, and the torque must be set to avoid side wall buckling.  Typical “thru-bolt” connections as shown below.

         

Torque values for “Thru-Bolts” are a function of:

Channel Bearing Strength to Avoid Sidewall Buckling

  • Nut Factor Coefficient of Friction (K) – Assumed 0.22 for EG Plating
  • Distance from the “Thru-Bolt” to Channel End

Single Channel Thru-Bolt Torque Limits

 

Double Channel Thru-Bolt Torque Limits