FASTSHIFTER Twister C4 structural screws 5×90mm 200 pcs

FASTSHIFTER Twister C4 structural screws 5 × 90 mm are outdoor framing screws in carbon steel with a C4 Ruspert coating, tested to 1500 hours salt spray. They are built for exposed timber structures and are also strong enough to fix thick 32–50 mm decking boards directly from the top.

Key features

• C4 Ruspert coating, 1500 h salt spray — extremely resistant to moisture and harsh weather.
• Double thread — pulls boards down tight and gives a gap-free connection.
• Countersunk head — seats without damaging the surface, for a clean finish.
• Drilling tip — prevents splinters and splitting.
• Dark brown finish — blends with most decking and framing timber.
• Suitable for thermally modified and pressure-treated timber alike.
• Supplied as 200 pcs + 1 bit (T25 drive).

Where it is used

• Deck substructures and outdoor timber framing.
• Thick 32–50 mm decking boards fixed from the top.
• Pergolas, carports, fences and garden structures.
• Thermally modified and impregnated timber in exposed positions.

Each pack includes a driver bit. For thick boards, fix two screws per joist and keep the distance from the board edge consistent — on wide boards this is what stops cupping.