Metallics DWC4M 6 x 15/8 in. Bugle Head Phillips Drywall Screws - Steel Black Phosphate - Coarse Threads - Each

No. The DWC4M is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your project carries a domestic sourcing requirement, this screw will not satisfy it.

No. Black phosphate is an interior finish only, and the Metallics DWC4M is a steel black phosphate screw. Phosphate gives a dry, paint and mud friendly surface and light corrosion resistance for inside work, but it will rust in wet or exterior exposure. For deck, exterior sheathing, or treated lumber, use a coated or stainless exterior screw.

That's what the bugle head is for. The DWC4M head measures 0.315 to 0.347 in. across with a head height of just 0.020 to 0.031 in., so the tapered profile pulls itself into the paper face and seats at or just below the surface without tearing it. Note that there is no single industry standard for bugle head dimensions, so slight deviations from those figures are normal.

The DWC4M is case hardened to Rockwell C45-64 and made from AISI 1018 steel, which is the standard drywall screw spec. That hardness keeps the Phillips recess from camming out under a drywall gun and lets the sharp point bite framing without a pilot hole. Like any hardened drywall screw it is brittle in shear, so it is not a structural fastener.

The DWC4M runs 8 to 10 threads per inch in a UNC coarse pattern. That wide spacing is what grips wood fiber, which is why it suits drywall to wood framing and wood to wood work. Fine thread screws, with a much tighter pitch, are the ones meant for light gauge steel studs, so match the thread to the substrate before you order a jar.

No special tooling, and Metallics includes a free power bit with each jar of DWC4M screws. The recess is a standard Phillips with a 0.106 in. depth and a 0.176 to 0.201 in. recess diameter, so a standard Phillips drywall driver bit engages it.