Spax universal countersunk screw 4.5x35 T20 Wirox

The typical SPAX T-STAR plus drive is a so-called internal hexalobular design. This shape increases the contact surface of the T-STAR plus screwdriver and ensures optimal positioning of T-STAR plus bits in the screw head. By enabling maximum power transmission from the screwdriver to the screw, T-STAR plus guarantees simple and extremely fast work that is much more efficient than with other drive types.

The flat countersunk head has a multi-sided underside ("pockets") that mills its way into the wood, allowing it to be countersunk without pre-drilling a pilot hole. The flat countersunk head sits flush with the surface.

Partially threaded screws are ideal for fastening thin components, such as wood-based panels, paneling, and floorboards, to thicker components such as rectangular timber or beams. The short thread penetrates the thick component, while the unthreaded shank remains in the fastened part. This creates maximum clamping pressure between the two. The unthreaded section should be at least as thick as the fastened part.

The term 4CUT refers to the arrow-shaped design of the screw tip. These edges displace wood fibers as the screw is driven in and create space for the screw core diameter. This reduces expansion in the wood core and helps prevent splitting around the edges. It also reduces the torque required from a cordless screwdriver, because the screw core no longer has to "force" itself into the wood.

With WIROX, SPAX has developed a coating that offers significantly better corrosion protection than galvanization. WIROX does not use chromium (VI), which means that even after years in environments not directly exposed to the weather, the screws remain just as durable while also being fully environmentally friendly. WIROX screws are the ideal choice for all open structures that are not directly exposed to the elements, such as carports and pergolas. For areas directly exposed to the weather, such as decks, we recommend our stainless steel screws.