#2 Phillips Bugle Head Drywall Screws — Black Phosphate, ASTM C1002, C1022 Carbon Steel
Nobody thinks about a drywall screw until one fails. Then it's all you think about.
Here's how it usually goes. You've got a crew on site, everything's moving, and suddenly screws start snapping at the head. Or worse — six months later the owner calls about bumps showing through the paint on a brand new wall. The screw itself costs almost nothing. The callback? That's a whole different number.
We've been making these things for over 20 years. The line starts with C1022 wire rod — drawn to diameter in our own shop, not bought off the shelf. Cold headers run multi-station progressive tooling. Parts come out the other end and go straight into a continuous atmosphere furnace. It's a tight cycle — the surface hits HRC 45–58 for drive torque, but the core stays in the high 20s, low 30s. You want a screw that's hard enough to bite but won't snap the instant the gun kicks.
The black phosphate coating. People ask about this all the time. It's not just for looks. Joint compound sticks to it. Paint keys into it. And for standard interior drywall — partitions, ceilings, soffits that aren't getting rained on — it holds up fine. If you're working in a wet area or coastal climate, we've got Ruspert-coated versions. They'll do 1,000+ hours in a salt spray chamber.
Packaging. We do bulk boxes for the high-volume drywall subs, collated strips that drop into Senco, Hilti, and DeWalt auto-feed guns, and private-label packs if you're a distributor putting your own brand on the shelf.
Every lot leaves with paperwork — mill cert from the wire rod heat number, dimensional conformance against ASTM C1002, hardness readings, coating weight. Not because anyone asked. Because that's how you stay out of trouble when something goes wrong on site and everyone starts pointing fingers.
If you buy containers, you've already learned this lesson the hard way: consistency is everything. Same wire source. Same tooling. Same furnace profile. Lot after lot after lot. That's the whole job.
Full Specification Table
| Size (Gauge × Length) | Diameter (mm) | Thread Type | TPI | Head Dia. | Drive |
|---|---|---|---|---|---|
| #6 × 1" | 3.5mm | Coarse | 16 | 8.0mm | #2 PH |
| #6 × 1-1/4" | 3.5mm | Coarse | 16 | 8.0mm | #2 PH |
| #6 × 1-5/8" | 3.5mm | Coarse | 16 | 8.0mm | #2 PH |
| #6 × 2" | 3.5mm | Coarse | 16 | 8.0mm | #2 PH |
| #6 × 1-1/4" | 3.5mm | Fine | 20 | 8.0mm | #2 PH |
| #6 × 1-5/8" | 3.5mm | Fine | 20 | 8.0mm | #2 PH |
| #8 × 1-1/4" | 4.2mm | Coarse | 13 | 9.5mm | #2 PH |
| #8 × 1-5/8" | 4.2mm | Coarse | 13 | 9.5mm | #2 PH |
| #8 × 2" | 4.2mm | Coarse | 13 | 9.5mm | #2 PH |
| #8 × 2-1/2" | 4.2mm | Coarse | 13 | 9.5mm | #2 PH |
| #8 × 3" | 4.2mm | Coarse | 13 | 9.5mm | #2 PH |
Size Selection & Usage Guide
| Drywall Thickness | Recommended Screw | Stud Type | Spacing |
|---|---|---|---|
| 1/4" (6mm) | #6 × 1" Coarse | Wood | 8" O.C. |
| 3/8" (9mm) | #6 × 1-1/4" Coarse | Wood | 8" O.C. |
| 1/2" (12mm) | #6 × 1-1/4" Coarse | Wood | 12" O.C. (field) / 8" O.C. (edge) |
| 1/2" (12mm) | #6 × 1-1/4" Fine | 20–25ga Steel | 12" O.C. (field) / 8" O.C. (edge) |
| 5/8" (16mm) | #6 × 1-5/8" Coarse | Wood | 12" O.C. (field) / 8" O.C. (edge) |
| 5/8" (16mm) | #6 × 1-5/8" Fine | 20–25ga Steel | 12" O.C. (field) / 8" O.C. (edge) |
| Double-layer 1/2" | #8 × 2" Coarse | Wood/Metal | 12" O.C. |
| 5/8" Type X Fire-Rated | #8 × 1-5/8" Coarse | Wood | 12" O.C. |
| Ceiling (single-layer) | #6 × 1-5/8" Coarse | Wood Joists | 12" O.C. (field) / 7" O.C. (edge) |
| Shear wall / Shear panel | #8 × 2-1/2" Coarse | Wood | Per engineer spec |
Note: Always consult local building code (IBC/IRC) for minimum fastening schedules. Spacings above follow ASTM C840 / GA-216 guidelines.
8. Applications
Residential
- Interior partition walls — single-family, multi-family, condos, townhomes
- Ceilings attached to wood joists and engineered trusses
- Basement finishing over wood or steel studs
Commercial & Institutional
- Office TI work — metal studs, gypsum board, the usual stack
- Hotels, hospitals, schools — anywhere fire-rated Type X board is spec'd
- Shaft walls and area separation assemblies
Industrial & Specialty
- Cleanrooms and lab partitions where you can't have fastener failures
- Acoustic isolation — resilient channel, double-layer board, sound-rated assemblies
- Temporary hoarding and site enclosures — screws you're not afraid to lose
OEM & Distribution
- Private-label packs for hardware distributors and wholesalers
- Collated strip supply for Senco, Hilti, and DeWalt screw gun platforms
- Retail SKU programs — blister cards, clamshells, bucket packs, shelf-ready display boxes
Why Choose Fasto?
- We've been doing fasteners for 20+ years. Not hardware trading — actual manufacturing. We own the wire drawing line, the cold headers, the thread rollers, and the heat treatment furnaces. If something's off, we fix it at the source, not at the QC station.
- IATF 16949 certified. That's an automotive-grade quality system running every production lot. We track from the wire rod heat number all the way to the carton label that leaves our dock.
- In-house lab. Universal tensile tester, Rockwell hardness, salt spray chamber, optical profile projector. Not subcontracted. It's in the building next to the production floor, and we use it every shift.
- Third-party tested to ASTM C1002, CE, SGS, RoHS. If you need an extra test we haven't run yet, just tell us what standard and we'll get it done.
- Dedicated OEM desk. Custom head marks, private-label packaging, bespoke coatings — Ruspert, Geomet, zinc flake. You send the artwork, we handle the rest.
- Lead times you can actually count on. 25–35 days for standard SKUs, 35–45 for custom. We keep buffer stock on the top 20 movers, so if your job site burned through faster than planned, we've probably got you covered.
Pain Points & Solutions
Screw Pops — The #1 Callback Problem
You finish a job. Paint goes on. Three months later the owner calls: bumps everywhere. Classic screw pops.
Most of the time it's not the drywall. It's one of three things. Either the screw got driven too deep and tore the paper face — that bond between the gypsum core and the fastener head is gone. Or the framing lumber dried out and shrank, pulling away from the shank. Or both.
Our bugle head has nibs underneath it. Sounds like a small detail, right? Those nibs create a controlled countersink that stops at the paper. Not through it. Pair that with a thread profile that stays locked in green lumber as it dries, and you've addressed the root cause instead of patching the symptom.
Head Snap During Installation
A screw that breaks halfway in costs you way more than the screw. You've got a guy on a ladder, gun in hand, and now he's fishing out a broken shank instead of moving to the next stud.
Nine times out of ten, head snaps come from uneven case hardening. The surface gets too brittle right at the transition from head to shank — and that's exactly where the stress concentrates when the gun torques out.
Our heat treat isn't a batch process where some screws come out perfect and others come out glass. We run a continuous controlled-atmosphere austempering cycle. Surface hits HRC 45–58 for drive torque. The core stays around HRC 28–40 — tough enough to bend before it breaks. And the head-shank transition zone gets dedicated process monitoring because that's where everything goes wrong if you're not watching.
Cam-Out — When the Bit Walks
A poorly formed #2 Phillips recess will eat your productivity alive. Bits wear out. Screws get half-driven and abandoned. Your installers start cussing.
Our recesses are cold-formed on precision-ground punches. We check them with go/no-go gauges every four hours during a production run, not just at the end. The bit seats deep and stays put at full RPM. Even in a ceiling corner with the gun at some stupid angle over your head.
Rust Spots on Interior Walls
Black phosphate screws aren't rated for exterior. Nobody's arguing that. But they shouldn't be bleeding rust through the paint on a living room wall either.
Cheap phosphate coatings are the problem. They wash off in the box or leave bare spots the size of a pinhead — and that's all moisture needs to start corrosion. We run a multi-stage zinc phosphate conversion coating followed by an oil seal post-treatment. Not one dip. Multiple stages.
For bathrooms, basements, coastal jobs — anywhere humidity hangs around — ask about our Ruspert-coated screws. 1,000+ hours neutral salt spray. They'll outlast the building.
Lot-to-Lot Inconsistency
The most expensive screw you'll ever buy is the one you can't trust. You open a box expecting 1-5/8" #6 and find mixed lengths, bent shanks, threads that strip on the first drive. Now your whole drywall schedule is sideways.
We ship a dimensional conformance report with every lot. Diameter. Length. Head diameter. Recess depth. Thread pitch. Hardness. Coating weight. Salt spray hours. You know what's in the box before you crack the tape.
Unreliable Lead Times
If your supplier's delivery window is more of a suggestion than a promise, you're carrying extra inventory just to sleep at night.
We run 25–35 days on standard SKUs, 35–45 on custom. Buffer stock on the top 20 items sits in the warehouse. For contract customers with a rolling forecast, we'll hold dedicated safety stock at no charge.
Container consolidation, too. Mix drywall screws with framing nails, deck screws, rivets. One shipment, one bill of lading, one set of customs docs.
FAQ
Pretty simple. Coarse thread (13–16 TPI) is for wood studs. The threads are deeper, so they bite into soft framing lumber and don't pull out as the wood dries and shrinks. Fine thread (18–20 TPI) is for metal studs. Tighter pitch, sharper crest — it engages thin-gauge steel without stripping the hole. Put a coarse thread into a metal stud and you'll just ream it out. Zero hold.
For 1/2" over wood studs: #6 × 1-1/4", coarse thread. Over 20–25 gauge steel: same size but fine thread. That 1-1/4" length gives you about 5/8" bite into the stud. Enough to hold, not so deep you risk hitting plumbing or electrical inside the cavity.
Three main causes. One: overdriving. The screw head breaks the paper face. Once that paper's torn, there's nothing connecting the gypsum core to the fastener anymore. Two: lumber shrinkage. The stud dries out after install and pulls away from the screw shank. Three: truss uplift, which is seasonal movement you can't really eliminate — but you can design around it. Prevention starts with depth control. The bugle head should dimple the paper, not destroy it. Consistent bugle geometry with nibs that limit overdrive makes a real difference. In high-moisture framing, using adhesive plus screws spreads the load across the whole panel instead of concentrating it at each fastener.
You can try. Here's why you probably shouldn't. Drywall screws are case hardened for speed — they're intentionally brittle. Put one under shear or bending load and it'll snap where a wood screw or structural screw just flexes. The thin shank and deep thread were built to resist gypsum board pull-through, not to hold a deck ledger or a cabinet to a stud. For framing, decking, cabinetry — use the right fastener.
Depends where you're using them. For standard interior drywall, black phosphate wins. It's cheaper and it grabs joint compound and paint better than zinc does — your finishers will notice the difference. Zinc-plated screws have slightly better corrosion resistance, so they show up in exterior sheathing specs sometimes. But if you really need corrosion protection, skip both and go Ruspert or ceramic. Zinc alone won't last outdoors. We stock all three finishes; tell us your climate and code requirements and we'll point you at the right one.
Standard 4'×8' sheet, 12" field spacing, 8" edges: about 32 screws. Ceilings tighten to 7" on the edges, so you're looking at 36–40. A 2,000 sq ft house burns through 8,000 to 12,000 screws. If you're quoting, one screw per square foot of drywall is a safe round number.
It's the ASTM standard for steel self-piercing tapping screws used in gypsum board. Covers material grade, hardness range, dimensional tolerances, thread quality, coating adhesion, corrosion resistance — the whole envelope. A screw marked ASTM C1002 was manufactured and tested to that standard. Our screws go through third-party testing against C1002 and every lot ships with conformance paperwork.
Korean projects usually reference KS B 1054 or KS D ISO 898 for fasteners. Our screws comply with ASTM C1002, which maps to the KS-equivalent requirements. We can provide KS-compliant test reports and documentation if the project needs local certs. For Korean importers and distributors: we do OEM packs with Hangul labeling, Naver-ready product data sheets, and trial orders starting at 500kg. No need to commit to a full container on the first go.