Description

Key Features

Cleaner Composite Fastening

The tri-lobe thread design and inverted upper threads are built to cut in cleanly and clear material as the screw drives. That helps reduce surface blowout and gives you a neater finished deck board.

Built for Composite Decking

This Simpson Strong-Tie composite decking screw is designed specifically for fastening composite deck boards. The cap head helps prevent mushrooming so boards finish flatter and look better.

Trex Approved Length

The 2-3/4 in. length is approved by Trex for Trex composite decking. If you’re matching fastener choice to board manufacturer requirements, that matters.

Overview

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.

Cleaner Results on Composite Boards

Composite decking can look great when it is finished right, and sloppy when the fasteners leave raised material around every hole. This screw is built to keep that from happening.

• Cap head helps prevent mushrooming for a flatter finished surface
• Tri-lobe thread design reduces damage to the composite board while driving

Fast Starts Without Fighting the Screw

The point and thread geometry are doing real work here. You get easier penetration into composite decking and cleaner pull-down as the screw seats.

• Type-17 point penetrates composite decking for fast starts
• Inverted upper threads clear excess material for a cleaner finish

Color-Matched for a Better Finish

On exposed deck surfaces, the head color is not a minor detail. Tan 01 is meant to blend better with compatible board colors so the finished deck looks more intentional.

• Tan 01 painted head for a less noticeable exposed fastener
• Quik Guard coating adds corrosion resistance for exterior decking work

Key Specifications

Screw Size	#10
Length	2-3/4 in.
Head Diameter	0.230 in.
Drive Type	T20 6-lobe
Head Type	Cap Head
Thread Type	Tri-Lobe Threads
Point Type	Type-17 Point
Coating / Material	Quik Guard Coating / Carbon Steel
Color	Tan 01
Packaging Quantity	70

Compatibility

Decking Material

Designed for fastening composite decking boards. Simpson Strong-Tie also states the DCU screw is suitable for all types of composite decking and PVC decking applications.

Trex Compatibility

The 2-3/4 in. length is approved by Trex for Trex composite decking.

Bit Interface

Uses a T20 6-lobe drive. Replacement bit part number is BIT20T-2-R2.

Built For

Deck Building Composite Decking PVC Decking Carpentry Remodeling General Contracting Exterior Projects Roof Sleeper Assemblies

Pro Tip

Use a fresh T20 6-lobe bit and stop driving as soon as the cap head seats cleanly. That lets the head do its job in composite decking and helps avoid overdriving the board surface.

Tool Nut’s Take

Tool Nut’s Take

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.

Common Questions

• 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.