Tirque settings for short nuts on panel mounted controls

[sparkylabs]

I've been asked to put torque settings on nuts that are holding switches onto panels and glands onto the back of boxes.

The supplier of the switch recommends 15pounds but that is only 1.6Nm which surely is ridiculous and is the same torque required to turn the switch so I'd think it risks loosening the switch again ?

I'm being advised 4-6 Nm for the M12 thread on the cable gland........

Usually we'd know what torque to apply but these are thinner nuts and the "bolt" is hollow plus I'm guessing it is not exactly bolt grade material.

Any ideas ?

 

[dinjin]

Test to see what torque is required to break or yield them and then use 70 percent of this value. Test several lots.

 

[sparkylabs]

We don't really have any to test on and the switches are quite expensive. We have settled on 4 Nm as that is the lowest torque we can set (yes very scientific I know....) and it seems to be nice and tight but not too tight to do any damage.