Wood screw Koelner/Rawlplug CS-8380 8×380 mm, washer head, construction fastener

Wood screw Koelner/Rawlplug CS-8380 8×380 mm with a washer head is a construction fastener designed for joining large timber elements and heavy carpentry tasks. The long threaded shank and robust geometry provide secure clamping and reliable pull-out resistance when used in treated and untreated wood. The washer head increases bearing surface for stable assemblies and reduces the risk of head embedment into soft timber.

Advantages

The long 380 mm length allows penetration through thick beams and multi-layer timber assemblies while maintaining strong axial load capacity. The washer head distributes load evenly, improving joint stability without additional washers. The screw’s thread design ensures efficient driving and firm grip in a variety of wood densities, delivering consistent fastening performance for structural connections.

Suitable for

• Framing and beam-to-beam connections
• Heavy carpentry and timber framing
• Attaching large planks, posts, and structural members
• Repair and reinforcement of existing wooden structures

Key specifications

• Diameter: 8 mm
• Length: 380 mm
• Head type: washer head for increased bearing area
• Material: suitable for use in treated and untreated wood (corrosion resistance depends on coating/type)
• Thread type: full/partial thread for strong withdrawal resistance and clamping
• Application: designed for structural timber connections and heavy-duty fastening

How to use

Pre-drill a pilot hole appropriate to the screw diameter and the density of the wood to reduce splitting, especially near edges or end grain. Position the components to be joined and drive the screw using a high-torque driver or impact wrench with the correct bit that matches the screw head. Ensure the head bears flat against the timber surface for optimum load distribution; avoid over-torquing to prevent crushing of softer wood fibers.

Usage recommendations

For structural applications, follow local building codes and engineering requirements. Select corrosion-resistant variants or additional protective measures when used outdoors or in humid environments. Use appropriate safety gear and verify load-bearing capacity when designing connections with long timber screws.