Starborn Industries Deckfast Metal (Cap-Tor xd Metal) - Brown (#34) - 350 pc. Deck Pack - 1-5/8" Self Drill - Type 410 Stainless Steel Deck Fastener for Use with Metal Joists & Trex Elevations

Why I reached for these screws

I’ve built and refit a fair number of decks on metal framing, and the fastener choice makes or breaks the job. For a recent composite-on-steel project, I ran the Deckfast Metal screws from Starborn in Brown #34—the 1-5/8 inch, self-drilling 410 stainless version. I wanted clean, color-matched faces on capstock decking, positive drive engagement, and reliable bite into steel joists without pre-drilling. That combination is harder to find than it sounds.

What they are

These are Grade 410 stainless, self-drilling deck screws designed specifically to fasten PVC, composite, and even hardwood boards to steel or aluminum framing. They use an extra-deep star drive (T-20) to reduce cam-out, and an undercut head that helps the head penetrate capstock and hardwood cleanly. The 1-5/8 inch length is a sweet spot for most modern 1-inch-class deck boards on steel or aluminum joists. They’re also approved for Trex Elevations steel framing and Wahoo’s DryJoist and DryJoistEZ systems, which aligns well with the kind of framing I see in retrofits and low-profile builds.

One note on design: as proper metal-framing screws, they don’t use “wings” like some wood-to-metal hybrid fasteners. The drill point handles the steel, and the threads do the rest. That’s the right architecture for this application.

Installation experience on steel and aluminum

I tested them across common scenarios:

• Composite capstock to 16-gauge steel joists (Trex Elevations)
• PVC boards to aluminum joists (DryJoist-style profile)
• A small run of dense hardwood boards to steel, just to gauge behavior

On the steel joists, the self-drilling point performed as advertised. With an impact driver on a low speed setting and a sharp T-20 bit, each screw established a pilot in the steel quickly and pulled down tight without wandering. In 16-gauge, bite happened in roughly two to three seconds of steady pressure. In thinner aluminum joists, the drilling was nearly instantaneous—easy to overshoot if you’re aggressive with the trigger.

On dense hardwood, I could drive without pre-drilling the board, but I preferred a 1/8-inch pilot near board ends to avoid any chance of splitting. The undercut head did help the head sink without mushrooming the surface fibers. For composite capstock, the undercut profile made a noticeable difference: the head seated flush with minimal to no “volcano” around the head—provided I slowed down for the last quarter turn.

Drive feel and head consistency

The extra-deep star recess is the right call. Most of the time, engagement was positive and cam-out was rare. I did run into some variability from screw to screw. A handful had slightly looser-fitting recesses that encouraged wobble under impact; a couple stripped early when I let the driver tilt. Using a fresh, high-quality T-20 bit minimized this—when I swapped to a new bit, the issue all but disappeared. Still, I’d plan on a small percentage of heads that feel softer or shallower than the rest.

Practical tips that helped:
- Use a compact impact driver on low speed with high axial pressure.
- Keep bits fresh; rotate as soon as fit feels sloppy.
- Back out and re-drive if you feel wobble in the first second—don’t power through.

Aesthetics and finish

The Brown #34 head coating blended nicely with common brown-toned composites. The heads seat nearly flush with a subtle shadow, not a crater. On capstock boards, backing off the trigger for the final eighth-turn gives the cleanest look. The coating held up well to the bit and occasional scrape on the deck surface, though you can still scar it if the bit slips. As with any color-matched screw, keeping the bit square is the best defense against scuffs.

Material choice and corrosion

Grade 410 stainless is the practical choice for self-drilling into metal—hard enough to cut and hold a thread, with corrosion resistance that’s generally sufficient for most deck environments. It’s magnetic and not as corrosion-resistant as 316, so for coastal or highly corrosive locations, I’d consider whether the environment warrants a different fastener strategy. In typical inland conditions, or when used with approved systems like Trex Elevations and Wahoo, I’m comfortable with 410.

If you’re fastening to aluminum framing, remember that stainless and aluminum can create a galvanic couple in salty or persistently wet environments. Follow the framing manufacturer’s guidance, maintain good drainage, and consider barrier tapes where appropriate.

Sizing and holding power

At 1-5/8 inches, these are well-sized for modern 0.9–1.0 inch deck boards. You get solid thread engagement in steel without an excessive protruding tip. I saw no tendency to back out over the first few months, and the clamping force felt consistent across the run. If you’re working with thicker decking or double-layer transitions, step up to a longer screw designed for metal framing rather than pushing these past their intended grip length.

Coverage and planning your count

The 350-pack is a logical unit for small to mid-sized jobs. Actual coverage varies with joist spacing, board width, and your fastener pattern. A quick planning formula:

• Screws needed ≈ 2 × number of joist crossings
• Joist crossings per board ≈ deck length in inches ÷ joist spacing in inches
• Total screws ≈ 2 × crossings per board × number of boards

Example: 12-foot boards over 16-inch-on-center joists
- Crossings per board ≈ 144 ÷ 16 = 9
- Screws per board ≈ 18
- If you have 20 boards, total ≈ 360 screws

In that common scenario, a single 350-pack gets you close; I’d buy a second box to cover waste, offcuts, stairs, and the occasional dud.

What I liked

• Self-drilling tip cuts reliably into 16-gauge steel and aluminum framing without pre-drilling
• Undercut head seats cleanly in capstock and hardwood with minimal mushrooming
• Deep T-20 star recess resists cam-out when paired with a quality bit
• Brown #34 color match looks clean and discrete on brown-toned composites
• Approved for Trex Elevations and Wahoo systems, which simplifies spec compliance

What could be better

• Some variability in the star recess fit; a few heads stripped more easily than expected
• 410 stainless is the right call for drilling performance, but it’s not the best choice for harsh coastal exposure
• Coated head can scuff if the driver walks; technique matters

Best practices for smooth installs

• Use a sharp T-20 bit and replace it at the first sign of wobble
• Keep the driver square and finish each screw at low speed to protect the head coating and avoid mushrooming
• For hardwood, pilot near board ends; for composites, slow down for the final set
• In thicker steel or doubled joist conditions, pre-drill the steel or use a longer fastener rated for that thickness

The bottom line

The Deckfast Metal screws hit the mark for composite and PVC decking on steel and aluminum framing. They drill, bite, and seat in a way that keeps faces clean and consistent, and the color match is genuinely helpful on visible surfaces. I did encounter occasional variability in the drive recess that led to a few stripped heads, which is frustrating on a long run, but manageable with fresh bits and good technique.

Recommendation: I recommend these screws for decks built on Trex Elevations, DryJoist-style aluminum, or similar metal framing, especially in typical inland environments. They offer the right combination of drilling performance, clean finishes, and compatibility with modern capstock boards. If you’re working in a coastal marine zone or you need absolute top-tier corrosion resistance, consider a different alloy and fastening approach. Otherwise, plan your count, keep a couple of extra bits on hand, and they’ll get the job done cleanly.