Attaching Jambs To Steel Columns

Whether you pre-drill the steel or use heavy self-tapping screws, you'll want to drill and plug the wood for the sake of appearance. October 17, 2011

I need to attach some 1-3/4" jambs to 1/4" steel columns. Welding studs onto the column is an option that I think may be too time consuming for the installer, so I was considering using self tapping screws. I don't want to use just adhesive. What do you think?

Forum Responses
(Architectural Woodworking Forum)
From contributor M:
If it was planned for correctly, you should have room for blocking on the steel - nail or screw it to the steel, and then install your jamb to it. You didn't give many details so I hope that works for you. Screws long enough to make it through your thick jamb and into 1/4 steel are not going to look anything close to a finish screw, and pre-drilling holes for those screws will save the muscle of forcing the big self-tapping through the jamb or blocking. If no blocking you'll probably need to make plugs to cover your screw heads. There's also concrete/steel nail guns for this type of attachment, but they're not considered finish guns.

From contributor B:
Pre-drill some 1/2" flat bottomed holes to receive 1/2" plugs, and try to locate some of the screws where the stops go and in the hinge leaf areas. Be sure not to put them where the screws go. Tek screws work quite well for this and are small enough to fit in the holes.

From contributor R:
You could drill and tap the steel. Drill through the wood and the steel at the same time with the tap drill, then take the jamb off and tap the steel. Use a little thread lube on the tap. I have also used the cordless drill to drive the tap. Works great.

From Gary Katz, forum technical advisor:
I'm with contributor B on this. We do it frequently, rarely with stop-applied jambs, mostly with rabbeted jambs, so there's plenty of meat to countersink the screw holes. Tek screws are great and never fail, not like Tapcons, which are touchy. Unless there's room for 2x blocking on the steel, you'll probably want to reach through the jamb and the 1x blocking with a screw.