Coarse Thread Drywall Screws Black Phosphate Bugle Head Plasterboard Screws Timber PH2

Coarse Thread Drywall Screws Black Phosphate Bugle Head Plasterboard Screws Timber PH2 Description

Coarse thread drywall screws for fixing plasterboard to timber studs and joists, made from hardened carbon steel with a black phosphate coating and driven with a standard PH2 Phillips bit - a professional-grade fixing suited to trade and DIY drylining work alike.

The coarse thread pattern is cut specifically to bite into timber - unlike a fine thread, which is made for driving into metal studs and channel. The wider-spaced, deeper-cut coarse thread displaces more wood fibre with every turn, giving a faster, more aggressive engagement in solid timber than the shallow, closely-pitched fine thread used on metal stud systems, so the screw grips the stud or joist firmly rather than stripping out under load. The carbon steel is hardened, giving the shank the strength to resist twisting off when driven under power-tool torque into dense timber. A self-tapping point starts its own way into the timber as it's driven, and the pan-style bugle head is shaped with a tapered underside that draws down into the plasterboard rather than punching straight through it, seating flush whether driven with a countersunk bit or a clutch-controlled driver. Driven correctly, the head finishes level with the surface for a clean, paintable result without tearing the plasterboard's paper face. The black phosphate coating gives corrosion resistance suited to interior use, and the screws are CE marked.

Key Features

• Hardened carbon steel construction for consistent strength and driving performance
• Black phosphate coating gives corrosion resistance for interior fixing applications
• Coarse thread profile cut specifically to grip timber studs and joists, rather than the fine thread used on metal stud systems
• Self-tapping point drives straight into timber studs and joists as the screw is driven
• Pan/bugle countersunk head with a tapered underside that seats flush with the board surface for a clean, paintable finish
• PH2 Phillips drive for secure bit engagement
• Spans three diameters (3.5mm, 4.2mm and 4.8mm) and eleven lengths from 25mm to 160mm, covering single-layer partitions through to deeper joist fixings
• CE marked

Specification

• Material: Hardened carbon steel · Coating: Black phosphate
• Drive: PH2 Phillips · Head: Pan/bugle countersunk
• Diameters: 3.5mm (0.14"), 4.2mm (0.17"), 4.8mm (0.19")
• Full length range: 25mm (0.98") to 160mm (6.30") across the three diameters, 11 length options in total
• Approx. unit weight: 1.2g per screw
• Certification: CE marked

• Diameter 3.5mm (0.14") - Length (mm): 25mm; Length (inch, approx.): 0.98"
• Diameter 3.5mm (0.14") - Length (mm): 35mm; Length (inch, approx.): 1.38"
• Diameter 3.5mm (0.14") - Length (mm): 45mm; Length (inch, approx.): 1.77"
• Diameter 3.5mm (0.14") - Length (mm): 55mm; Length (inch, approx.): 2.17"
• Diameter 4.2mm (0.17") - Length (mm): 70mm; Length (inch, approx.): 2.76"
• Diameter 4.2mm (0.17") - Length (mm): 90mm; Length (inch, approx.): 3.54"
• Diameter 4.8mm (0.19") - Length (mm): 100mm; Length (inch, approx.): 3.94"
• Diameter 4.8mm (0.19") - Length (mm): 120mm; Length (inch, approx.): 4.72"
• Diameter 4.8mm (0.19") - Length (mm): 140mm; Length (inch, approx.): 5.51"
• Diameter 4.8mm (0.19") - Length (mm): 150mm; Length (inch, approx.): 5.91"
• Diameter 4.8mm (0.19") - Length (mm): 160mm; Length (inch, approx.): 6.30"

Typical Applications

These screws are for fixing plasterboard and drywall sheets to timber studs and ceiling joists, covering the full range of timber-frame drylining work:

• Stud wall and partition wall construction, fixing plasterboard directly to the timber frame
• Ceiling linings, fixing plasterboard up into timber ceiling joists
• General timber-frame drylining and refurbishment work
• Single-layer plasterboard fixing, best suited to the shorter 3.5mm-diameter lengths (25-55mm)
• Thicker board build-ups, multiple layers of plasterboard, or fixing through board into deeper sections of structural timber, suited to the 4.2mm lengths (70-90mm) and heavier 4.8mm lengths (100-160mm)

Across the full diameter range of 3.5mm to 4.8mm and lengths spanning 25mm to 160mm, the range covers most stud and joist spacings and board thicknesses encountered on standard domestic and light commercial partition and drylining jobs.

Installation Guidance

Fit a PH2 Phillips bit to a clutch-controlled or depth-adjustable driver and drive the screw until the head sits level with the surface of the plasterboard's paper face, without breaking through it - this keeps the fixing flush and ready for jointing and painting, and avoids the torn, blown-out heads that come from overdriving. The self-tapping point means the screw drives straight into the timber stud or joist without a separate pilot hole.

When selecting a screw, choose a length that passes fully through the board thickness and secures a solid length of penetration into the timber stud or joist behind it, and size the diameter to the job - the 3.5mm screws for standard single-board fixing, moving up to 4.2mm and 4.8mm where a longer length or heavier board build-up is involved.