US4 - #10 x 2-1/2" Gray Stainless Steel Bugle Head Screws | T25 Star Drive | Self-Drilling Screws for Framing, Subflooring & Decking | 305 SS

A stainless option that’s built for everyday exterior work

I put a box of US4 stainless deck screws to work on a handful of small projects—some deck-board replacements, a bit of subfloor fastening over a squeaky run, and a couple of fence picket repairs—spread across a weekend. By Sunday evening, I had a solid sense of where these screws shine and where they ask for a little finesse.

What stands out

• The T25 star drive is properly cut. The included T25 bit seated crisply with almost zero wobble, and I didn’t experience cam-out even when driving at awkward angles overhead.
• The points are extremely sharp. They bite immediately and track straight, which matters when you’re trying to start a screw one-handed on a ladder or in a tight corner.
• They’re 305 stainless, and they pass the quick magnet test I use to confirm austenitic stainless. For decks, fences, and general exterior use, 305 is a good balance between corrosion resistance and cost.

The screws come in a 100-count box, sized #10 x 2-1/2 inches, finished in a neutral gray that blends with weathered softwoods and doesn’t scream for attention against joists or hardware.

Drive performance and holding power

In pressure-treated southern yellow pine, these screws are as close to “effortless” as I’ve used in stainless. The self-drilling tip (a wood-cutting style) starts cleanly and pulls itself in without skittering. I drove a dozen through fresh PT deck boards into joists; each seated just below the surface with a neat crater, thanks to the bugle head. No mushrooming and no split ends in boards—even near the edges—so long as I respected the usual edge distances.

On 3/4-inch tongue-and-groove subfloor over joists, the #10 shank provides a reassuring pull-down. I use stainless sparingly indoors, but I wanted to see how they behaved into dry framing. They cinched squeaks with fewer fasteners than I expected, and I never stripped a head. That star recess is cut well, and the steel feels tough enough to handle a cordless driver’s higher-speed settings without chewing up the recess.

Old, dry lumber is a different challenge—dense and unforgiving. Into seasoned fir from a decades-old bench frame, the screws still bit and drove, but they demanded steadier pressure and a slower trigger to keep torque under control. I had one screw bend slightly when I rushed a drive into end grain. Backing off, aligning carefully, and letting the bit work solved it.

Hardwood reality check

These are labeled for hardwood and thermally modified wood. In my tests on beech and a scrap of white oak, the point started aggressively, but torque spiked midway through and one screw snapped just past halfway. That’s not unusual for stainless fasteners in tough hardwoods; stainless is corrosion-resistant but generally less forgiving in sheer torque than hardened carbon steel. The takeaway: pre-drill in dense hardwoods, especially near edges, or choose a dedicated hardwood decking screw designed to handle those loads. For softwoods and typical treated decking, these are great; for truly dense decking species, they need a helping hand.

Corrosion resistance and finish

305 stainless is widely used for deck and exterior screws. It handles wet climates and most backyard chemistry well. If you’re in a coastal zone with airborne salt or expect prolonged salt exposure, 316 stainless is the safer bet, but you’ll pay for it. For inland decks, pergolas, fences, and general exterior framing, 305 is the right balance.

These screws arrived clean and consistent. Threads were free of burrs, the star recesses were all cut true, and the gray finish is low-glare. The shanks are not coated—this is stainless, not painted carbon steel—so there’s nothing to flake off or chip.

Wood vs. metal claims

The box calls out wood and metal fastening. These behave like wood screws with a self-drilling (type-17 style) point. They zip through wood beautifully and will bite thin, soft sheet metal—think flashing or light angle—but I would not rely on them for steel studs or thicker sheet. If you truly need a stainless screw for consistent metal work, look for a TEK-point stainless fastener designed for that job.

Also note: these aren’t a substitute for code-listed structural fasteners. For joist hangers, ledger connections, or shear-critical framing, stick with the manufacturer-specified nails or specialty screws. I’m more than happy to use these for deck boards, subfloors, fence pickets, fascia, pergola slats, and assorted trim.

Day-to-day usability

• Bit engagement: Excellent. The T25 recess is deep and well-formed, and the included bit is a nice touch.
• Speed: Fast in softwoods. The screws pull themselves in, and I rarely needed to “feather” the trigger.
• Countersink: Clean. The bugle head sets just below the surface without tearing fibers around the head.
• Consistency: Every screw I grabbed matched the last in point, thread, and recess quality.
• Safety: The tips are needle sharp. Keep them in a small parts bin or the original box; don’t pocket them.

What could be better

• Dense hardwood behavior: In species like white oak, beech, or thermally modified boards, plan to pre-drill and control torque—or consider a different fastener optimized for hardwoods. These can bend or snap if forced.
• Metal work expectations: The “wood and metal” claim can be read generously. For regular metal fastening, choose a dedicated stainless TEK screw.
• 305 vs. 316: Not a knock, but a point of fit. If you’re in harsh marine environments, these wouldn’t be my first pick.

Tips for best results

• Use the included T25 bit and let the driver do the work. If the screw stalls, back it out a quarter turn to clear chips, then continue.
• For hardwood decking or thermally modified lumber, pre-drill pilot holes roughly the minor diameter of the screw, and consider a countersink if you want perfect, flush heads.
• Avoid overdriving in softwood. Set your clutch or stop once the head is just below flush to preserve holding power and avoid crushing fibers.
• Store the screws dry, even though they’re stainless. It keeps the points sharp and free from handling grime.

Who they’re for

• DIYers and pros who work primarily in softwoods: pressure-treated pine, doug fir, cedar.
• Exterior projects: decking, fence pickets and rails, pergola slats, fascia, exterior trim that benefits from stainless fasteners.
• Subfloor fastening where corrosion resistance or long-term serviceability matters.

If your work centers on ipe, cumaru, beech, oak, or thermally modified decking, you can still use these—just pre-drill consistently or opt for a hardwood-specific stainless screw.

Value

Stainless always costs more than coated carbon steel. The tradeoff is durability: no flaking coatings, better resistance to acids in treated lumber, and long-term appearance that won’t rust bleed into surrounding material. In a 100-count box, these make sense for small to medium projects or targeted repairs. For building an entire large deck, you’ll likely want a larger count box from the same line or a bulk option.

The bottom line

The US4 stainless deck screws are excellent everyday exterior fasteners for softwood projects. They drive fast and straight, resist cam-out, seat cleanly, and offer the corrosion resistance I expect from 305 stainless. Their limitation, like many stainless wood screws, shows up in dense hardwoods where pre-drilling becomes necessary and the margin for driving errors narrows.

Recommendation: I recommend these screws for framing, decking, subflooring, and exterior carpentry in softwoods and typical treated lumber. They deliver reliable drive performance, clean finishes, and long-term corrosion resistance. If you’re working primarily with dense hardwoods or in coastal marine environments, consider pre-drilling or stepping up to a hardwood-optimized or 316-grade alternative.