SPAX universal screw, countersunk head 4x40/23 T20 Wirox

The typical SPAX T-STAR plus drive is a hexalobular internal drive. This design 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 transfer from the screwdriver to the screw, T-STAR plus ensures simple and extremely fast work that is much more efficient than with other drive types.

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

Partially threaded screws are ideally suited for fastening thin components, such as wood panels, boards, and floorboards, to thicker components such as rectangular timber beams or joists. 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 the wood fibers as the screw is driven in and create space for the screw core diameter. Expansion in the wood core is reduced, which helps prevent splitting around the edges. The torque required from the cordless screwdriver is also reduced, because the screw core no longer has to "force" its way into the wood.

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