250 Countersunk Wood and Solar Screws – Inox A2 – 4.2x35/20 – TX20 – SK Drill

Versatile outdoor fastening: The SK Drill solution for timber and solar

Designed to withstand the rigors of exterior environments, these Inox A2 stainless steel screws offer exceptional resistance to corrosion and weather. Their versatile design makes them a preferred choice for both traditional woodworking, such as terrace construction, and specialized technical applications like mounting solar panel brackets. The 35 mm length is specifically suited for securing thinner boards or metal components firmly into wooden supports.

Precision engineering for efficiency and material care

The SK Drill range incorporates several technical features to ensure a professional and stress-free installation:

• Anti-fissure technology: A specialized notch at the start of the thread acts to prevent internal tension in the wood. This significantly reduces the risk of cracks and fissures, even when working near the edges of the material.

• Low-torque driving: The screws are finished with a special lubricating coating. This reduces friction during insertion, allowing for lower driving torque and less physical effort, which also preserves your power tool’s battery life.

• Instant thread engagement: The point is designed for rapid biting into the timber, ensuring the screw starts immediately without slipping across the surface.

• Stable TX20 drive: The six-lobe internal TX20 (Torx) drive provides a secure, wobble-free connection from the moment the screw is placed until it is fully countersunk, preventing bit slippage and head damage.

Key advantages:

• Corrosion protection: Premium Inox A2 steel for long-term outdoor reliability.

• High structural strength: Boasts a tensile strength of 700 N per mm2 for heavy-duty anchoring.

• Material integrity: Thread notch prevents splitting and relieves stress in the timber.

• Metal-to-wood excellence: Perfectly suited for attaching metal supports, clips, or roof hooks to wooden frames.

Technical characteristics

• Quantity: 250 pieces

• Diameter: 4.2 mm

• Total length: 35 mm

• Thread length: 20 mm

• Head type: Countersunk

• Head diameter: 7.6 mm

• Head height: 3.65 mm

• Drive type: TX20 (Torx)

• Material: Inox A2 stainless steel

• Tensile strength: 700 N per mm2

• Features: Thread notch and low-friction coating

Professional tips

• Solar applications: When using these screws to fix roof hooks or solar brackets, ensure the 20 mm thread length provides sufficient engagement into the structural rafter for a secure, wind-resistant hold.

• Decking usage: For wooden terraces, the countersunk head allows the screw to sit flush or slightly below the surface, creating a clean finish that is safe for foot traffic.

• No pre-drilling: While the thread notch minimizes splitting in most softwoods and standard timbers, pre-drilling is still recommended for very hard or brittle woods to ensure a perfect aesthetic result.

• Driver bit quality: Always use a high-quality TX20 bit to take full advantage of the wobble-free drive system and prevent unnecessary wear on the screw heads.