I bought these screws at HD which were next to the blue concrete screws. They said "wood to metal" but they had a self tap drill tip, then, oddly enough, there was some other flare that stuck out just after the drill tip and just before the threads. THEN, the threads. I found this extra flare to be designed to bore out through wood but I think when it hits the metal it blows a hole too big and the threads don't contact.

What should I use to fasten(securely) a 2x4 to a sheetrock wall that is mounted to steel studs(standard commercial)?

 

Depending on what the 2x4 will be used to support, you could use #8x2 1/2" decking screws. The points will self drill adequately through the thin metal studs.

 

I would probably suggest 2 1/2" fine thread drywall screws. The fine threads are made to hold into metal studs, and also have a sharp point to pierce the metal. Either way, a bit of construction adhesive behind the 2x4 would probably be advisable if you never want it to come off.

 

I used the drywall screws (fine thread) because I had some. They work but I must say, they don't tighten and snug like a screw in wood. It almost seems like you have to be very careful not to strip out the metal stud. sucky.

But thanks!

 

Construction adhesive, if you plan on it being permanent and want to put some weight on it. Then the screws

 

Interior steel studs are not structural, at least not ones you can screw into with just pointed screws. If this is going to carry weight, you need to use toggles or drywall anchors like "Togglers"