Steel studs are often used in commercial construction as well as in some residential homes. These studs are cheaper and lighter than wood studs and perfectly straight. They resist fire, bugs and decay, fitting together like a child's toy. You won't know they're metal when the studs are clad in drywall -- until you hit one with a nail or screw when attempting to hang something. Most screws and nails won't penetrate through steel studs. Drilling a hole is required.
Why You Need to Drill
It might be that you're hanging a flat-screen television, pictures or mirrors on the wall -- or installing drywall inserts for a variety of reasons. Self-tapping drywall inserts or anchors work fine to hang things on metal studs clad in drywall. But even though they penetrate drywall just fine, they won't tap into metal studs without drilling a hole -- but you have to find it first.
Locate the Stud
Locate metal studs with an ordinary stud finder, and then locate the center of the stud. Common stud spacing for metal studs should be 12, 16 or 24 inches on center. The stud finder will give you a relatively precise location, but metal studs are typically only 1 1/4-inches wide, and drilling a hole near the edge can compromise the stud, or result in the failure of the hole.
Find the Edge, Then the Center
Use a small drill bit, or even a finish nail inserted into a drill/driver, to drill holes in the drywall on each side of the stud to pinpoint the edges. It may require punching a few holes to accomplish it -- you can patch them later with caulk or even toothpaste. When you find both sides, mark the center of the stud.
Drill Bit Type
Almost any drill bit penetrates steel studs, but using the wrong bit can result in ruining the bit, or a rough, jagged hole. Use cobalt, oxide, titanium or carbide-tipped twist bits for the best results. They're often colored bright gold or silver and will penetrate steel studs over and over again cleanly and without significant wear.
Screw vs. Gauge
You don't need to drill holes to hang drywall; drywall screws penetrate without pilot holes. Use fine drywall screws to hang drywall on steel studs with a 20- to 25-gauge rating. Use self-drilling drywall screws on 12- to 20-gauge studs. These types of screws have a sharper-than-average tips, with finer threads to deter stripping in metal, plus finer threads grip metal better than standard threads. Space screws 8 inches apart along edges and 12 inches on center everywhere else.
Pilot holes are necessary for baseboard or other wood trim. Once you've located the stud, place the trim in position, drill a 1/4-inch countersink hole, and then follow up by drilling through the trim only -- don't drill into the stud -- with an 1/8-inch bit. Use 1 1/2-inch, self-drilling trim screws to attach the trim to the drywall and studs.
Plumbing and Electrical Holes
Carpenters rely on hole saws for larger holes in studs for electrical and plumbing. But ordinary hole saws won't cut through metal efficiently, if at all.
Use a hole saw designed for metal. This type of hole saw has hardened teeth, with less aggressive, closer-spaced teeth to cut cleaner holes -- think of a hacksaw blade -- so the saw is less likely to bind.
Metal Stud Punch
If you're uncomfortable with a hole saw, the metal stud punch may be just what you're looking for. This device is just like an ordinary paper punch, except bigger and meaner to allow it to punch holes in steel. It's quick and efficient.