
Factory Price Carbon Steel Hardened Bugle Black Phosphating Gypsum Drywall Screw. Wood thread drywall screws (coarse thread) Thread: Coarse, wide pitch Use: Fasten drywall to wood studs joists. Feature: Quick penetration, strong holding power in wood Metal thread drywall screws (fine thread). Thread: Fine, narrow pitch Use: Fasten drywall to light gauge steel studs. Feature: Prevents stripping in thin metal framing. Self drilling drywall screws Built in drill tip Use: Directly drill into thin metal without pre drilling. Bugle head (standard): Rounded countersunk head, most common; does not crack drywall paper Flat head: For heavy duty applications. 25 mm (1 in): Thin single layer drywall 32 mm (11/4 in): Most standard interior drywall 38 mm (11/2 in): Double layer drywall or thicker board 45 mm(13/4 in): Ceiling drywall or heavy duty. Phosphate coated (black grey): Standard indoor drywall screw; anti rust for normal dry environments. Zinc plated: Better corrosion resistance, for damp areas Stainless steel: For wet rooms, bathrooms. Installation Tips Drive the screw head slightly below the drywall surface (dimpled), not breaking the paper. Differences from Ordinary Wood Screws Thinner shank, sharper point, finer threads.