Metallics SDS4M 6 x 15/8 in. Bugle Head Phillips Drywall Screws - Steel Zinc - Fine Threads - Each

The Metallics SDS4M is a self-drilling and self-tapping screw, so it forms its own hole in light gauge steel without a pilot. The screw point type is a drill point, and the stated field application covers wood, drywall, steel and aluminum. That is what separates it from a plain sharp-point drywall screw, which will walk on steel and snap the head before it bites.

Fine thread is what you want on steel framing, and the SDS4M is fine thread at 18 threads per inch, UNF. The tighter thread pitch holds in thin metal where a coarse thread just spins out. Coarse thread is the wood stud screw. If your job is drywall over wood framing, this is the wrong pick.

A #2 Phillips. The recess is 0.106 inch deep and 0.176 to 0.201 inch across, which is standard #2 geometry, and a power bit comes with the jar so a crew starting a run is not hunting for one. Worth noting if you are buying several jars: you get a bit with each.

That is the whole point of the bugle head. The curved underside of the head compresses the paper face rather than tearing it, and it seats just below the surface so joint compound covers it. Head height runs 0.020 to 0.031 inch with a head width of 0.315 to 0.347 inch. A flat or pan head screw in the same application leaves a bump you cannot hide under tape.

The SDS4M ships as a jar of 1,000, which is the order minimum. Other sizes and quantities are available by request, so if you are standardizing a multi-building spec on this screw and need a different length or count, that is worth asking about rather than substituting a different screw mid-job.

No. The SDS4M is not Buy American compliant and is not ARRA compliant, with multiple countries of origin. On a federally funded job with domestic sourcing language in the spec, this screw will not pass submittal review, and that is a decision to make before the jar is opened rather than at inspection.

Zinc plating over steel gives light corrosion resistance, enough for interior work including normally humid rooms once they are finished and ventilated. It is not a coating for exterior use, wet exposure, or treated lumber contact, where the plating gives up and you get rust bleeding through the finish. The SDS4M is steel with a zinc finish, built to AISI 1018.

The SDS4M is case hardened to Rockwell C44, which is the hardness that lets a drill point cut steel without rolling over. That same hardness is why you want a depth-setting nose on the gun: a hard screw driven too deep will keep going and tear the paper rather than stall. Set the clutch so the head just dimples the face.

A full jar of SDS4M runs 5.25 lbs, in a container measuring 4.5 x 7.25 x 4.5 inches. Light enough to carry a few at a time on a punch list, and small enough that a case of them stacks in a van without eating a shelf.