weldable nuts 1

[gte447f]

I have a situation where I need to weld a nut to a beam web to receive a threaded rod "thru-bolt" that will transfer tension/compression forces from the threaded rod to the beam web. One side of the beam web is not accessible, so a double locking nut arrangement is not possible. The threaded rod will be A36 steel. What nut material should be specified that is both compatible with the A36 threaded rod and weldable? I understand that high strength (i.e. heat treated) nuts should not be welded. Is this all a A563 nuts, or are there some grades of A563 that are weldable? What is the proper designation for nuts made from A36 steel if there is one?

 

[TVP]

There are a variety of grades within ASTM A563. Grades O, A, and B can be used for hex and square nuts, and are low enough in strength that welding is possible. I suggest you specify the nut something like this:

Grade O (or A, or B) according to ASTM A563
C = 0.23% maximum
Mn = 0.90% maximum
S = 0.025% maximum
P = 0.020% maximum

This will eliminate steels that will have too much hardenability (C content from 0.23-0.55%), as well as free-machining steels like 12L14, etc. that have poor weldability.

 

[kingnero]

there are nuts with a lip ( or zero chamfer instead of a radius) on one side, that are ment to be welded.
I've seen them but don't know to what standard they are made...

 

[MiketheEngineer]

They are readily available commercially. Look around

 

[Tmoose]

Will the threaded rod be perpendicular or parallel to the web?

 

[bernoullies123]

I welded plenty of A194-2H for a similar kind of purpose without any indication of cracking.

 

[gte447f]

Tmoose, the threaded rod will be perpendicular to the beam web.

So far, I have instructed the contractor to select a commercially available "weld nut" and submit for review prior to welding. We will see what they come with? If they cannot come up with anything acceptable, I will probably take TVP's approach above.