Torque of austenitic 304 bolts in aluminum beams of geodesic dome 8

[ll23]

Greetings, I hope somebody can help me with this one, I am in a project involving the erection of a geodesic aluminum roof, is necesary to aply torque to the stainless steel fastners of the estructure of the dome, this is the node and the beam, both of aluminum, AA 5454 H34 and AA 6061 T6, the bolts are A2-70 1/2".

 

[CWB1]

Have you observed how torquing (an indirect and at best crude measure of pre-stress) is often done on the ground?

I handled field support for a construction machinery OEM in the third-world for several years. Much as I like to jokingly compare my current environment working in various UAW plants, I don't believe maintenance nor repair gets any more crude than in developing nations.

As to fasteners, in the realm of mechanical design a bolted joint analysis is commonly a junior engineer's task and often special fastener design is as well. Many companies today have in-house fastener testing capability and outsourcing is very common as well. This isn't a black art, the impact of common adhesives and lubricants on torque and bolt stretch is well understood.

 

[SnTMan]

Wonder how the OP is making out

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

Again, what facilitates yielding of any bolt is an un-trained installer and poor QC.

°
So we are pretty much in agreement.

CWB1,
I don't disagree with anything you are saying, I'm saying I don't see nearly enough of those practices in my neighbourhood. I watched an international bridge being fastened with not a lot more than torque wrenches.
Nevertheless, I stand by my statement that austenitic SS bolts are inherently more problematic.

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[TimSchrader2]

Hello If your making something for a ocean boat stainless bolts and screws are a standard. I have a Max torque chart, but would need to scan it.

We have made quite a few cranes with stainless bolts on the main bearings. If loads are high we will spend the $ on 17-4 bolts.