Simpson Strong-Tie Deck-Drive DCU COMPOSITE Screw, #10 x 2-3/4-in. T20, Quik Guard, Tan 01, 70-Pack (DCU234TN01R70) is a hand-drive composite decking screw made for fastening composite deck boards with a cleaner finished look. This is a composite decking screw designed for deck board fastening. Model Number: DCU234TN01R70. For deck builders, remodelers, and serious DIY users working with composite or PVC decking, the point of this screw is simple: drive easier, leave less mess at the surface, and end up with a more professional-looking deck.

What sets the DCU screw apart is how the thread and head work together in composite material. The tri-lobe thread design helps reduce damage to the board while driving, and the inverted upper threads clear excess material on the way in. In real use, that means less tearing and less buildup around the top of the hole. The cap head is there for the same reason. It helps prevent mushrooming and keeps material from pushing up above the deck surface, which is a common headache when fastening composite boards.

The Type-17 point is built for fast starts in decking material, so the screw gets moving without a lot of skating or wandering. Pair that with the T20 6-lobe drive and you get solid bit engagement, which matters when you are driving repeated fasteners across a full deck. Better drive engagement means less cam-out, less stripped recesses, and less time fighting the screw instead of finishing the job.

This version uses Quik Guard coating over carbon steel for corrosion resistance suited to medium-corrosion environments. That makes it a practical fit for many exterior deck builds where you need protection beyond plain steel. The painted Tan 01 head is also part of the value here. On composite decking, color matters. A closer head match makes the finished surface look cleaner and less distracting than a bright exposed fastener.

On the sizing side, this screw is a #10 x 2-3/4 in. fastener with a 0.230 in. head diameter and a 70-piece package count. The 2-3/4 in. length is specifically called out as an approved fastener by Trex for Trex composite decking, which gives buyers a clear compatibility reference when they are trying to stay inside manufacturer guidance. Simpson Strong-Tie also notes that the DCU line is available for hand-drive applications and in collated versions for the Quik Drive system, so the platform makes sense whether you are handling a small repair or standardizing across larger deck installs.

Who should buy this one? Anyone building or repairing composite decking who wants a screw made for the material instead of forcing a generic exterior screw to do the job. It is a good fit for deck crews, carpenters, remodeling contractors, and homeowners replacing boards or building smaller sections. If appearance matters, if you want less mushrooming, and if you want a screw approved for Trex at this length, this is the right type of fastener to be looking at.

Simpson Strong-Tie Deck-Drive DCU COMPOSITE Screw is the right fix for ugly composite fastener holes

If you're building composite decking and care what the finished surface looks like, this screw earns its keep.

• Who it's for: Deck builders, remodelers, and homeowners fastening composite or PVC deck boards and wanting a cleaner exposed-fastener finish.
• Why it stands out: The tri-lobe thread, inverted upper threads, Type-17 point, and cap head are all aimed at the same goal: easier driving and less mushrooming in composite material.
• Worth knowing: This is a 70-pack hand-drive screw, so it makes sense for smaller jobs, repairs, punch-list work, or matching an existing fastener color without buying a bulk bucket.

• Is this screw approved for Trex decking? Yes. Simpson Strong-Tie states that the 2-3/4 in. DCU length is an approved fastener by Trex for Trex composite decking.
• What driver size does it use? It uses a T20 6-lobe drive. Simpson Strong-Tie lists replacement bit part number BIT20T-2-R2.
• What material is this screw intended for? It is designed for fastening composite decking boards, and the DCU line is described for composite and PVC decking applications.
• How many screws are in this package? This SKU includes 70 screws.