Wood screw Koelner/Rawlplug CS-8120 8x120 mm, washer head, for timber connections

Koelner/Rawlplug CS-8120 is a wood construction screw 8x120 mm with a washer head designed for timber connections. The screw is intended to join wooden elements in structural and carpentry applications, offering axial load transfer and a large bearing surface thanks to the integrated washer-style head. It is suitable for use with pre-drilled pilot holes and can also be used with softer wood species where self-tapping performance is adequate.

Advantages

The washer head increases contact area between the screw and the timber, reducing the risk of head pull-through and distributing clamping force evenly. A threaded shank provides secure axial fixation and improved withdrawal resistance in structural timber joints. The screw’s length and diameter deliver deep embedding for strong load-bearing connections, and its design simplifies installation when joining beams, posts or planks.

Suitable for

• Joining structural timber elements such as beams and joists
• Carpentry and woodworking assemblies
• Fixing exterior and interior wooden frames and supports
• Repairing and reinforcing wooden structures

Key specifications

• Diameter: 8 mm
• Length: 120 mm
• Head type: washer-style head for increased bearing area
• Intended material: wood and timber components
• Threaded shank for axial load transfer and withdrawal resistance

How to use

Select an appropriate pilot hole diameter if working with hardwood or when specified by structural requirements; for softer wood species the screw may perform in a self-tapping mode. Position the timber elements to be joined, align the screw perpendicular to the contact surfaces, and drive the screw until the washer head sits flush or slightly countersunk against the timber surface. Use a power screwdriver or drill with a suitable bit and torque setting to avoid over-tightening and damaging the wood.

Usage recommendations

For load-bearing connections follow applicable building codes and fastening guidelines. Where corrosion resistance is required, choose screws with appropriate protective coating or stainless variants. Pre-drill in hardwoods and maintain recommended edge and end distances to preserve timber strength.