Set of Koelner/Rawlplug construction screws 3.5x35 mm with partial thread and countersunk head, supplied as 30 pieces. These fasteners are designed to join wood and thin metal elements while providing a flush finish thanks to the countersunk head. The package contains screws intended for structural and general carpentry tasks such as framing, fixture installation and light assembly where a neat surface and secure hold are required.
Advantages
The partial thread profile concentrates clamping force on the unthreaded shank portion to pull two materials tightly together, reducing gaps and improving joint stability. The countersunk head allows the screw to sit flush with or below the workpiece surface for a clean appearance and easier finishing. Supplied in a pack of 30, the set is convenient for small to medium projects and reduces the need to buy individual screws repeatedly.
Suitable for
- Joining wood-to-wood connections in carpentry and furniture assembly
- Attaching thin metal sheets or profiles to wooden substrates
- Framing, substructure assembly and fixing brackets or fixtures
- Applications requiring a flush countersunk finish for painting or covering
When it may not be suitable
These 3.5x35 mm screws with partial thread are not intended for heavy structural loads or load-bearing steel-to-steel connections. They are sized for light to medium carpentry; use longer or larger-diameter fasteners for thicker materials or higher shear and withdrawal requirements. For applications exposed to severe outdoor environments, consider corrosion-resistant grades if the supplied finish is not rated for prolonged weather exposure.
Key specifications
- Length: 35 mm
- Diameter: 3.5 mm
- Thread type: partial (incomplete) thread
- Head style: countersunk (flat when installed)
- Quantity in pack: 30 pieces
- Intended materials: wood and thin metal elements
How to use
Pre-drill pilot holes when working with hardwoods or near edges to reduce splitting; choose a drill bit diameter slightly smaller than the screw core. Drive the screws with an appropriate screwdriver bit or a compatible power driver set to moderate torque to avoid over-tightening and head cam-out. Position the countersunk head so it sits flush with the surface; if a fully recessed finish is required, use a countersink tool before fastening. Check alignment of joined parts and tighten progressively to achieve even clamping.
What to consider before purchase
- Match screw length and diameter to material thickness and load requirements
- Confirm whether the screw finish suits indoor or outdoor use and exposure to moisture
- Consider pre-drilling needs for hardwoods or thin metal to prevent damage
Usage recommendations
For reliable joints, use the partial-thread screws to pull pieces together while allowing the unthreaded shank to act as a dowel-like alignment. When installing into hardwood or close to edges, pre-drill and use controlled torque. Store the remaining screws in a dry place to avoid corrosion and keep the correct driver bit handy to prevent head damage during installation.
