Torque/ tightening force for NON-Preloded bolts (regular bolts) 2

[KubusKubus]

Hello all,

I would like to ask what is the Torque/ tightening force for NON-Preloded bolts (regular bolts). I have a standard tension connection. There is a lot of guidelines what is the torque value to achieve 75 % of yield load.
But I can't find what is the standard value of the torque (with particular friction coefficient) to tighten bolts as much to not get loose during work life.
Only value which if found is for bearing connection which is very ambiguous:

Tightening of the bolts: connected elements should be cling together. Tolerance less than 2 mm
is acceptable if this is not give in design recommendations. Bolts should be manual tightening
till “first point of resistance”. First point of resistance is defined as a tightening nominal hand
wrench with one hand power.

 

[WinelandV]

Could you please guide me if in this case should I use pretension torque value instead of snug-tighten torque value?

(emphasis added by me)

I can't give you a torque value for a pre-loaded bolt. The torque is going to depend on a variety of factors that, in the U.S., we don't even try to account for. We either have the erectors calibrate a torque wrench in a skidmore device, use TC bolts (or other direct tension indicators), or turn the nut a set rotation beyond the snug tight condition (turn-of-nut method).

What codes are you building this structure to? If it's AISC, then you can use the Research Council on Structural Joints Using ASTM A325 or A490 Bolts for how to achieve the proper pretension in your bolts. If Canadian, then I THINK that it's within their steel code. I am unfamiliar with Euro and British standards, so someone from that side of the pond will have to point you in the right direction.

 

[DAVIDSTECKER]

If you have a canopy subject to wind cyclic loading then you want to torque the bolts to the 75% yield to reduce cyclic fatigue.