Bolts For Connection Of Bracings 4

[ypzhang]

Hello everyone,

I have a question about the connection for the bracings:

Some people use the slip-critical bolts for the connection of bracings, some people use bearing-type bolts, which is right?

Thank you very much!


Best regards,


Ping

 

[JAE]

Either are "right". Generally engineers prefer to use tightened bolts on bracing to minimize slip and reduce any secondary deflections due to the slip in the bolt connections.

 

[swearingen]

Slip critical bolting is also mandatory under certain seismic and fatigue considerations.



If you "heard" it on the internet, it's guilty until proven innocent. - DCS

 

[nutte]

For seismic design, slip critical faying surfaces and bolt pretension is required, but the bolts can still be designed as bearing bolts.

Bearing bolts are stronger than slip critical bolts. If you call for slip critical, expect more bolts.

 

[Dinosaur]

I would say the allowable stress (strength) used for design is higher when checking Type N (or Type X) bolts verses Type F bolts. Since it is the same bolt, I don't agree that the bolt is 'stronger.' Also, there is a lot of confusion about when you may use the Type X values, and I have convinced engineers and contractors in the past they don't want to go there. I don't recall the last time I used other than a Type F. Good luck!