Wood screw Koelner/Rawlplug CS-8300 8x300 mm, washer head, construction screw

Koelner/Rawlplug CS-8300 construction wood screw, size 8x300 mm with a washer head, is designed for secure mechanical connections in heavy timber work. The screw is intended to fasten beams, large timber elements and structural wooden joints where deep penetration and strong clamping force are required. It is suitable for indoor and sheltered outdoor timber joinery when combined with appropriate pre-drilling, corrosion protection and installation tools.

Advantages

The washer head provides a broad bearing surface that reduces the risk of head pull-through and distributes pressure evenly across the timber surface. The long 300 mm length allows connection of thick sections and multilayer assemblies in a single fastener, reducing the need for multiple shorter screws. Designed for structural use, the screw delivers high shear and withdrawal resistance when installed following recommended pre-drilling and embedment depths.

Suitable for

• Fastening beams and large cross-sections in timber frames
• Connecting structural wooden elements and heavy carpentry joints
• Timber-to-timber connections in indoor and sheltered outdoor applications
• Repair and reinforcement of wooden structures and decking subframes

Key specifications

• Diameter: 8 mm
• Length: 300 mm
• Head type: washer head for increased bearing area
• Designed for mechanical load-bearing timber connections
• Requires pre-drilling appropriate to timber species and thickness

How to use

Select a drill bit size and pre-drill pilot holes appropriate for 8 mm diameter screws and the timber species to avoid splitting. Place the screw in position and drive using a power screwdriver or impact driver with compatible bit and torque control; avoid excessive torque to prevent head damage. Ensure sufficient embedment depth into the receiving member and maintain alignment of connected elements during installation. For connections exposed to moist environments, apply appropriate corrosion protection methods and use compatible treated timber or protective coatings.

Usage recommendations

Follow structural design guidelines for spacing, edge distances and embedment depths. Use corrosion-resistant fasteners or additional protection when installing in humid or partially exposed locations. When in doubt, consult a structural engineer or timber construction professional to confirm required screw quantity and pre-drilling dimensions for load-bearing applications.