Metallics DWSR7M 8 x 2-1/2 in. Bugle Head Square Drywall Screws - Steel Black Phosphate - Coarse Threads - Each

Coarse thread, sharp point, which is the wood-stud configuration. The DWSR7M is specified for drywall-to-wood applications. For drywall over light gauge steel studs you want a fine thread (S-point/self-drilling) screw instead, since coarse threads chew through sheet metal rather than grip it.

Yes, for a single 1/2 in. sheet it is overkill. The DWSR7M at #8 x 2-1/2 in. is sized for thick build-ups, double layer board, or drywall-over-wood furring and plywood where you need real penetration into the stud. For single layer 1/2 in. board, a 1-1/4 in. screw is the normal call. Metallics offers other lengths in the DWSR series.

No. Black phosphate is a dry interior coating, it gives mild handling protection and paint adhesion, not corrosion resistance. The DWSR7M is a steel black phosphate screw for interior drywall and wood work. For exterior decks, wet rooms, or treated lumber, use a coated deck screw or stainless instead.

No. The DWSR7M is not Buy American compliant and is not ARRA compliant, with country of origin listed as multiple. If your contract carries domestic sourcing language, this fastener will not qualify.

A #2 square (Robertson) bit. The recess runs 0.110 to 0.113 in. wide and 0.064 to 0.075 in. deep, so a #1 will cam out and a #3 won't seat. Square drive is the reason a lot of hangers pick these over Phillips, the bit stays put one-handed on a screw gun.

That is what the bugle profile is for. The head measures 0.315 to 0.363 in. across with a head height of 0.020 to 0.039 in., so it dimples the paper and sits just below the surface for mud instead of cutting through it. Set your gun depth so the head is slightly recessed, not driven through the face.

AISI 1018 steel, case hardened to Rockwell C45-64. That hardness is what lets the sharp point bite without a pilot hole, but it also means the shank is brittle if you overdrive or hit a knot or a nail. In dense hardwood or engineered lumber, pre-drill or back the gun clutch off.

UNC coarse thread at 8 to 10 threads per inch. That wide pitch is what pulls board tight to wood framing in fewer turns and holds in softwood end grain; it is also why it is the wrong choice for metal studs.

No single industry standard exists for drywall screw or bugle head dimensions, so Metallics publishes the figures as a guide and slight deviations are acceptable. Practically, that matters if you are specifying to a tight head diameter or recess depth, the ranges given (head 0.315 to 0.363 in., recess 0.110 to 0.113 in. wide) are the tolerance band, not a fixed number.