Wood construction screw Koelner/Rawlplug 8x140 mm washer head, model CS-8140

Wood construction screw Koelner/Rawlplug 8x140 mm washer head, model CS-8140 is a heavy-duty fastening element designed for structural wood connections. The 8 mm diameter and 140 mm length provide deep threaded engagement for secure joins in solid timber, laminated beams and heavy carpentry. The washer (flanged) head increases bearing surface and helps distribute load on wooden surfaces to reduce the risk of pull-through and surface indentation during installation.

Advantages

This construction screw offers a combination of strong mechanical hold and straightforward installation. Its long threaded shank ensures reliable penetration into thick members, while the washer head improves load distribution. The screw is suitable for use where shear and tensile resistance are important, delivering consistent performance in timber framing and beam assembly tasks. The design allows use with power drivers and reduces the need for additional washers in many applications.

Suitable for

• Timber framing and roof truss fastening
• Joining beams, posts and laminated timber
• Heavy carpentry and structural woodwork
• Deck and platform substructure where deep penetration is needed
• Applications requiring increased bearing area at the head

Key specifications

• Diameter: 8 mm
• Length: 140 mm
• Head type: Washer (flanged) head to increase bearing surface
• Application material: Solid wood, laminated timber and structural wood elements
• Drive compatibility: Suitable for use with power drivers or impact drivers (use appropriate bit)

How to use

Pre-drill pilot holes when working near edges or with hardwood to prevent splitting; select a drill bit slightly smaller than the screw core diameter. Position members accurately, clamp if necessary, and drive the screw until the washer head sits flush against the wood surface without over-tightening. For repetitive installation, use a torque-limited driver or set an appropriate clutch setting on the power tool to avoid stripping. Ensure fasteners are placed according to structural spacing and edge-distance requirements relevant to your project.

Usage recommendations

Use corrosion-resistant or coated fasteners for exterior or humid environments and follow structural design recommendations for spacing, embedment depth and load capacity. When fastening across glued laminated timber or engineered wood products, verify manufacturer guidance for fastener type and embedding requirements.