Wood construction screw Koelner/Rawlplug CS-8340 8x340 mm, washer head

Wood construction screw Koelner/Rawlplug CS-8340 8x340 mm with a washer head is a long-threaded fastener designed for structural timber connections and heavy-duty wood assemblies. Its deep thread profile ensures secure bite into soft and hard woods, while the extended length and robust shank allow transfer of significant shear and tensile loads. The washer head provides increased bearing surface to reduce pull-through and improve clamping of timber elements in beams, posts and decking.

Advantages

The screw offers dependable holding power through an optimized thread form and full-length engagement appropriate for long timber joints. The washer head increases contact area for better load distribution and reduces surface damage to wooden members. Made for both indoor and outdoor carpentry, the fastener is suitable for applications requiring durable connections and consistent performance under sustained load.

Suitable for

• Structural timber connections (beams, rafters, posts)
• Decking and terrace construction
• Heavy-duty framing and load-bearing wooden assemblies
• Timber repair and reinforcement where long fasteners are required

Key specifications

• Diameter: 8 mm
• Length: 340 mm
• Head type: washer head for increased bearing surface
• Thread: deep, full-length thread for strong wood engagement
• Material/coating: designed for carpentry use (suitable for indoor and outdoor applications)

How to use

Pre-drill a pilot or clearance hole appropriate to the wood species and screw diameter to avoid splitting, especially near edges or ends. Align the timber elements to be joined and clamp if necessary. Drive the screw using a compatible bit and appropriate torque, ensuring the washer head sits flush against the wood surface for optimal load distribution. When installing outdoors or in exposed conditions, use appropriate corrosion-resistant fasteners or coatings and follow local building codes for structural connections.

Usage recommendations

For reliable structural performance, select pilot hole diameter and embedding depth according to timber type and joint design. Use washers or plates where additional bearing capacity is needed, and verify fastening spacing and edge distances per relevant construction standards.