I need to bolt 2x8s to an 8" steel beam. I am going to use 1/2" bolts. Can I drill 1/2" holes in the beam or would that be too tight to get the bolts through?

Thank.

You can use a 1/2". If it is too tight you can use a step drill or taper reamer to open the hole a bit. Filing with a rat tail file would also work.

I agree, or drill your holes 7/16ths to begin with. Make sure you use flat washer on the wood side and a flat, and lock washer on the nut side. What is this for?

Thanks ma0641 and talaniman. This is a residential remodel. We're removing bearing walls and replacing them with steel beams. Beams go in the joist space so the wood is for blocking to reconnect to existing joists.

7/16" is too small. I was considering 9/16" just so I don't have to ream 40 holes. The blocking is going to be resting on the bottom flange of the beam (W8X40) anyway. I just wasn't sure if loose bolts would compromise the integrity of the beams. Here is a picture.

Do either of you have any experience working with steel beams?

My bad, I surely meant 9/16ths, and there are a few ways to get away from all that hole drilling for wood filler. They have a few joist hanging methods to consider.

https://www.bing.com/images/search?q...10&FORM=IDBQDM

Anchoring a wood plank on top of the I beam allows for a variety of joist hangers to be used.

https://tse1.mm.bing.net/th?id=OIP.h...4&pid=3.1&rm=2

https://tse1.mm.bing.net/th?id=OIP.R...4&pid=3.1&rm=2

This would be my preference unless a structural engineer clears drilling holes.

There's no room to put anything on top of the beam. Holes are not a problem, as the steel fabricator is doing it. Thanks for the input.

Well, if the fabricator is punching the holes, the answer is easy.

I was under the impression you were doing this yourself, and in the planning stages of this project, but if you have a contractor it's likely going to be already planned out with their own tried and true methods of operation. The size of the beams used are determined by the loads they carry taking into account the number of holes that had to be drilled into them to accommodate any extra tie ins like the joists, or even other load bearing beam, or structures.

In my experience this was always laid out after the job was scoped out, and an estimate was prepared for the client, which always included a bill of materials and labor, plus time. Just curious as to what are your concerns in regards to the way your contractor is doing things?