Wood screw Koelner/Rawlplug TS-3520 3.5x20 mm conical head TX drive for wood fastening

Koelner/Rawlplug TS-3520 is a 3.5x20 mm wood screw with a conical (countersunk) head and a TX (Torx) drive designed for flush, durable wood fastening. The conical head allows the screw to sit level with or below the wood surface, while the Torx drive improves torque transfer and reduces the risk of cam‑out during installation. This screw is suitable for a wide range of carpentry and furniture tasks where a neat, secure finish is required.

Advantages

The conical head provides a discreet, flush finish appropriate for visible surfaces and interior joinery. The Torx drive enables higher torque application with reduced slippage, making installation faster and more controlled. The 3.5x20 mm dimensions offer a balance between holding power and minimal splitting risk in common wood materials. The screw’s thread geometry is optimized for wood engagement to ensure reliable clamping of wooden parts.

Suitable for

• Furniture assembly and repair
• Interior joinery and trim work
• Cabinetry and shelving installation
• General carpentry and wood-to-wood fastening

Key specifications

• Length: 20 mm
• Diameter: 3.5 mm
• Head type: conical / countersunk head for flush mounting
• Drive type: TX (Torx) drive for improved torque transfer
• Intended use: fastening in wood and wood-based materials

How to use

Select an appropriate Torx driver matching the TX size of the screw. For precise results, predrill a pilot hole in dense or brittle woods to reduce splitting; choose a pilot diameter appropriate to the wood type and screw diameter. Position the screw and drive it in with steady pressure until the head sits flush with or slightly below the surface, taking care not to over-torque which can damage the material or strip the driver. For visible finishes, countersink first if necessary to achieve an even surface.

Usage recommendations

Use compatible Torx bits and a controlled-speed driver for best results. When working with hardwoods or veneers, consider predrilling and countersinking to protect the workpiece. Store screws in a dry place to avoid surface corrosion if they are not coated for exterior use.