Standard torque

[foglights]

I recently encountered a situation where an MS20007 bolt was used in conjunction with an MS21043 fiberlock nut. Going off an SS9300 torque chart the bolt was in the 160,000 psi column and the nut in the 125,000 psi column and therefore had very different torques - approx a 200 inlb difference.

In this situation, which torque value is used?

The application is an S-61 tail landing gear mount where the bolt is in shear. The maintenance manual does not specify an torque for this unique situation

 

[desertfox]

Hi foglights

I would have expected the lower torque value to be used.
That said usually figure given off charts are maximum for that particular fixing but the joint application may not require the fixing to be at its maximum torque.
Each joint should be calculated and analysed before setting a torque figure or preload.

desertfox