SPAX countersunk universal screw 3.5x15 T20 Wirox (1000 pcs/pack)

The SPAX T-STAR plus drive ensures maximum power transfer to the screwdriver—thanks to its unique hexalobular design, work is fast, precise, and slipping is a thing of the past. The bit’s perfect fit in the screw head makes repetitive fastening easy and efficient.

A slim yet durable head is especially important when installing window and door frames. The full-thread SPAX-RA screw is designed specifically for this purpose—it fastens without plugs and allows for a clean finish without protruding heads.

The full thread extends along nearly the entire length of the screw, allowing it to withstand significantly higher tensile and compressive loads than a partial-thread screw. This makes it an excellent choice for demanding wood joints, for example in structural applications—without unsightly metal connectors.

The 4CUT point shapes the screw tip like an arrow, allowing the wood fibers to be cleanly displaced during insertion. This reduces the risk of splitting, especially near edges, and lowers the torque required from the tool—in most cases, pre-drilling is not necessary.

Outdoor use demands durability from screws. The WIROX coating provides excellent corrosion protection without environmentally harmful chromium(VI). WIROX screws are the ideal solution for structures that are outdoors but not directly exposed to the elements, such as pergolas and carports. If the structures are directly exposed to rain and moisture, we recommend stainless steel screws.