Where to find required dimensions for washers/nuts for snug tight A325 bolts?

[StructureMan44]

Where can I find the required dimensions for washers/nuts for snug tight A325 bolts? I found the nut dimensions in the AISC RSCS but not the requirements for adding two nuts instead of one.

 

[CoryPad]

The required dimensions for the nuts are in ASME B18.2.2, while those for the washers are in ASTM F436.

For two nuts, do you mean using a double nut arrangement to prevent loosening?

 

[StructureMan44]

Thank you very much CoryPad. Yes, I have seen double nut arrangements and I don't know what is the requirement for doing this.

 

[Duwe6]

Go onto the internet and download a copy of RCSC's spec.

http://www.boltcouncil.org/files/2009RCSCSpecification.pdf

Never a need for double-nuts. Not a need for washers for 'snug-tight' or 'turn-of-the-nut' IF the holes are round [not short-oval holes]. If holes are short-oval, hard washers are required over the oval side.

BUNCH of misinformation and 'Old Wives Tales' out there on structural bolting. Follow the RCSC spec and grin at the idjits. Bolting is simple, until somebody gets stupid.

 

[CoryPad]

The RCSC specification was updated in 2014, here is the link to the document:

http://www.boltcouncil.org/files/2014RCSCSpecification-2014.pdf

There is no requirement for double nutting, but it is used in some applications that have force fluctuations and not enough fastener clamping force to resist those fluctuations. A good example is poles (lights, flags, traffic signals, etc.). Threaded anchor rods protrude from the ground and nuts are placed on them, then the pole baseplate, make sure the baseplate is level by adjusting the lower nuts, then add more nuts on top of the baseplate and tighten. But you cannot generate much clamping force because the joint is short and stiff, rather than long and compliant. So, another nut is added on top of the joint to prevent loosening from force fluctuations such as those that occur during very windy days.