I want to use light gage steel studs as part of a window buck system. The problem I see is that to drill holes to mount the windows I would have to drill through steel and then the concrete directly behind it. Does anybody know of a drill bit that will actually do this and do it well?

Clif

Why not use a powder actuated system, such as Hilti?

Try to place your bucks so that the foam from the ICF is directly behind the exterior and interior steel. This should prevent fasteners of any kind from contact the concrete. Much like the "flange" on VBuck goes over the foam.

Rereading this, I missed ther window mounting part, I thought you were mounting the metal stud to concrete.

As I don't use metal studs as mounting points, especially for areas where wind is an issue, I would need to see a detail as to how you are compiling this buck.

Are you inserting the stud into the wall cavity, then bracing(a lot) for the pour, ending up with the metal/concrete issue?

I would like to insert a 6" steel stud into the space between the foam panels. The steel will be secured with Wind Devil washers with screws through the foam. Inside the opening will be some type of plastic lumber. Lots of bracing of course. The concrete will lock with the return flange on the stud and the screws through the foam. I think there are diamond bits that might work for drilling the holes to mount the windows, but I was hoping there would be an easier way. I would just use V-Buck but I would have to use their 1 1/4 by  1 1/4 internal PVC reinforcing at $2.50 a foot not to mention having to buy the V-Buck in 480 foot quanities from local suppliers. V-Buck looks like a great product but the price gets rather high.  After seeing a local pour with pressure treated wood and the severe warping I am not even considering wood.

Clif