Bolting a steel beam to another steel beam.

[vincentianpinner]

The first beam has been in a while it's got a plate welded with the holes for the bolts. Then needs another one attached to form a T shape. The first one is nice and plumb and I assume the second one will be square and true but it occurred to me that once it's screwed tight it might be off slightly and not giving a perfect 90 degrees.
My question is, is there any way of adjusting it slightly if that's the case? Possible where the washers go?

 

[stevie888]

Always best to fit all steels at the same time if you can to avoid this worry.

You may need to add some shims between the plates if you have a misalignment. Unless you have a really bad fabricator and or installer of first beam you'll only need very thin sheet: maybe cut up a baked bean tin.