The best metal roofing screws for most exposed-fastener panels are ST Fastening’s ZXL WoodBinder #10, a ZAMAC-capped, EPDM-sealed screw that carries a lifetime red-rust warranty on the head. The right screw still depends on what you fasten into (wood purlins or steel), your corrosion zone, and whether the job needs FM or Miami-Dade approval. Below are seven ranked picks, each with published specs, a price range, and the one use case it wins.
How we picked the best metal roofing screws
This roundup is built from published manufacturer specifications, recognized corrosion standards (the 1,000-hour salt-spray benchmark that painted and coated heads are measured against), listed code approvals (FM, SDI, Miami-Dade), and aggregated contractor and buyer sentiment. We did not run hands-on lab or field testing of these fasteners.
Treat these rankings as a specifications-and-reputation guide rather than a controlled test result. Coating performance, drill-point behavior, and pull-out values vary by panel gauge, substrate, and installation torque, so confirm current pricing and code approvals with the manufacturer before placing a large order.
Best metal roofing screws at a glance
The table below compares the seven picks by gauge, head and coating type, sealing washer, listed approvals, and price range. Fastener pricing is quoted per screw based on 250-count bags or 100-count boxes and can shift with steel costs, so use these as planning figures. Fastener costs also move with steel prices, which our metal roofing tariff and import report tracks in detail.
| Screw | Best for | Gauge / size | Head & coating | Washer | Approvals | Price range |
|---|---|---|---|---|---|---|
| ST Fastening ZXL WoodBinder #10 (Top Pick) | Exposed-fastener panels into wood | #10, 1″ to 2″ | ZAMAC 5 dome cap, lifetime red-rust warranty | Vulcanized EPDM, UV-shielded | Manufacturer warranty | $0.10 to $0.22 / screw |
| ST Fastening Maxx SteelBinder #12 | Metal-to-metal on steel purlins | #12, combo 2-and-3 point | Powder coat over zinc + chromate | Cupped hex EPDM | FM, SDI, Miami-Dade | $0.10 to $0.26 / screw |
| Triangle Fastener BLAZER HWH | Code-approved commercial jobs | #12 to #14 bi-metal | TRI-SEAL + KALIDA-KOTE | Bonded EPDM | FM, SDI, Miami-Dade | Quote via TFC distributor |
| SFS Bi-Met 300 | Coastal and saltwater zones | 304 stainless body, carbon point | 304 stainless, self-drilling | EPDM available | Marine-grade build | Quote / premium tier |
| SFS Impax SD3 #12 | Color-matched long-life commercial | #12 self-drill | VistaCoat, exceeds 1,000-hr salt spray | Cut EPDM washer | Salt-spray rated | $0.12 to $0.20 / screw |
| Teks #9 / Hillman Power Pro #10 | Budget and same-day DIY repairs | #9 to #10, 1-1/2″ | Painted steel over zinc | Bonded EPDM | Retail stock | ~$15 to $17 / 100 |
| ZXL #12 T-17 WoodBinder | Replacing failed or stripped screws | #12, Type 17 point | ZAMAC 5 dome cap, Strip-Loc thread | Vulcanized EPDM | Manufacturer warranty | ~$70 / 250 |
1. ST Fastening ZXL WoodBinder #10: best overall
The ST Fastening ZXL WoodBinder #10 is our top pick for exposed-fastener metal panels installed over wood purlins or plywood, which covers most agricultural, pole-barn, and residential standing-seam-adjacent jobs. Its ZAMAC 5 zinc-aluminum dome cap resists red rust even if the coating is scratched on the way in, and the EPDM washer is vulcanized to the cap so its edges are not left exposed to UV.
Best for: panels that need to outlast a 40-year painted-steel warranty without the head failing first.
- Pros: lifetime red-rust warranty on the cap; encapsulated EPDM that resists drying and cracking; color caps that match most panel lines; wide length range from 1″ to 2″.
- Cons: costs more per screw than a home-center painted-head option; sold mainly through fastener distributors rather than big-box retail.
2. ST Fastening Maxx SteelBinder #12: best for steel purlins
The Maxx SteelBinder #12 is the pick when you fasten metal panels directly to steel purlins or tube framing rather than wood. Its combination 2-and-3 drill point self-drills through steel up to about 0.210″ thick without the point walking across the panel, and it carries FM, SDI, and Miami-Dade approvals for commercial specifications.
Best for: pre-engineered metal buildings and commercial re-roofs over steel.
- Pros: drills thick steel cleanly; triple code approval; 2.5-mil powder coat over zinc with a chromate sealer.
- Cons: the powder-coat head does not carry the lifetime red-rust warranty of the ZAMAC-capped WoodBinder; overkill for wood substrates.
3. Triangle Fastener BLAZER HWH: best for code-approved commercial
Triangle Fastener Corporation’s BLAZER HWH is the go-to when a project spec demands FM or Miami-Dade documentation and you want a bi-metal option. It pairs a 410 or 304 stainless body with a hardened point and a TRI-SEAL plus KALIDA-KOTE coating system, and it is sold with the engineering data that inspectors and specifiers often require.
Best for: hurricane-zone and FM-insured commercial roofs where paperwork matters as much as the screw.
- Pros: bi-metal corrosion resistance; strong approval documentation; distributor engineering support.
- Cons: quote-based pricing with no published per-screw figure; usually ordered through TFC channels, not off the shelf.
4. SFS Bi-Met 300: best for coastal and saltwater
Within roughly three miles of salt water, thin zinc-plated screws can begin rusting within months, so a stainless build is worth the premium. The SFS Bi-Met 300 uses a 304 stainless body with a hardened carbon-steel point, giving the corrosion resistance of stainless with enough point hardness to self-drill. For the harshest marine exposure, a full 316 stainless screw in the substructure adds molybdenum for extra protection.
Best for: beachfront and marine-air roofs, and aluminum panels where dissimilar-metal corrosion is a concern.
- Pros: stainless body rated for decades in C4 to C5 corrosion zones; self-drilling carbon point; EPDM washer available.
- Cons: premium price; still verify galvanic compatibility with the specific panel metal.
5. SFS Impax SD3 #12: best color-matched long-life commercial
The SFS Impax SD3 #12 suits commercial roofs that need a painted, color-matched head with a coating that exceeds the 1,000-hour salt-spray benchmark. Its VistaCoat finish is built to hold color and resist chalking longer than a standard polyester powder coat, which helps the fastener heads age at the same rate as the panel.
Best for: visible commercial roofs where head appearance over 20-plus years matters.
- Pros: salt-spray-rated coating; broad color range; consistent supply for repeat commercial buyers.
- Cons: a painted head can still chalk faster than a molded ZAMAC cap; best value when you already buy from SFS.
6. Teks #9 or Hillman Power Pro #10: best budget and DIY
For a small repair or a same-day fix, home-center screws such as the Teks #9 x 1-1/2″ or Hillman Power Pro #10 x 1-1/2″ cost roughly $15 to $17 per 100 and are stocked at most big-box stores. They use a painted steel head over zinc with a bonded EPDM washer, which is adequate for short-term repairs and color touch-ups but not the choice for a full new roof meant to last decades.
Best for: patch repairs, DIY sheds, and jobs that need parts today.
- Pros: cheapest per screw; available immediately; color options for common panel shades.
- Cons: the washer edge is exposed to UV and can dry out sooner; shorter red-rust life than ZAMAC or stainless heads.
7. ZXL #12 T-17 WoodBinder: best for replacing failed screws
When you re-screw an aging roof where the original #9 or #10 holes are wallowed out, an oversized replacement screw restores the grip. The ZXL #12 T-17 WoodBinder uses a Type 17 self-piercing point and a Strip-Loc thread to bite into an enlarged hole, and its larger diameter and 1″ oversized EPDM options seal over a worn seat. Expect about $70 per 250 versus roughly $38 for standard #9 screws.
Best for: retrofits, backing-out screw callbacks, and high-wind re-fastening.
- Pros: larger diameter re-grips stripped holes; ZAMAC cap; self-piercing point for re-drives.
- Cons: higher cost per screw; only needed on repair and retrofit work, not new installs.
How to choose the right metal roofing screw
Picking a metal roofing screw comes down to four decisions: what you fasten into, the corrosion zone, the head and coating, and the length. Match all four and almost any reputable brand performs. Miss one, and the roof can leak or the heads can rust years before the panel does.
Self-drilling versus self-piercing points
Self-drilling screws have a fluted drill point that bores through steel purlins without a pilot hole, which is why they suit metal-to-metal work up to about 0.210″ of steel. Self-piercing (Type 17) screws have a sharp gimlet point that pierces wood and thin sheet fast, so they are the choice for panels going into wood purlins or for re-seating replacement screws. Using a self-piercing point on thick steel usually leads to point walking and stripped threads. For a deeper look at one common self-drilling line, see our guide to Teks self-drilling roofing screws.
Head coating: ZAMAC and ZAC versus stainless versus painted zinc
Head material drives how long the fastener looks and seals well. A molded ZAMAC or ZAC zinc-aluminum cap resists red rust and will not chalk or fade like paint, which is why the warranty-grade screws use it. Stainless heads win in coastal air. Painted-steel heads over zinc are the budget tier and can chalk or show rust sooner, especially where the coating is scratched during driving.
The EPDM washer is the waterproofing
The rubber washer, not the threads, keeps water out of the fastener hole. A vulcanized or encapsulated EPDM washer that is bonded into a cupped head resists UV, drying, and cracking far longer than a flat bonded washer with exposed edges. Set the screw so the washer compresses to the edge of the cup and no further; overdriving squeezes the rubber out and underdriving leaves a gap, and both cause leaks. On fall-protection hardware that also fastens through the roof, our best roof anchor roundup applies the same corrosion-zone logic.
Gauge and length by panel
Most exposed-fastener roofing panels use #9, #10, #12, or #14 screws, with #10 and #12 the common residential and light-commercial choices. Length should let the screw penetrate the substrate by at least 3/4″ but not much more than 1″. For a typical panel over wood, 1″ to 1-1/2″ is standard; over thicker framing or through insulation, step up to 2″ or longer. Confirm the exact call-out against your panel and framing before ordering; see our guides to R-panel roofing and tools for metal roofing for panel-specific specs and the drivers that seat these screws to the right depth.
How many metal roofing screws do you need per square?
Plan for about 80 metal roofing screws per square (100 square feet) on a standard 36-inch exposed-fastener panel set at 24 inches on center, and up to 90 to 100 per square in high-wind or heavy-snow zones. A fast estimate is roof area in square feet times 0.80. The exact count depends on the panel profile and the field-versus-eave fastening pattern the manufacturer specifies, so confirm the layout before you order.
The table below sets out the common exposed-fastener profiles, the field pattern each uses, and the resulting screws per square, based on published installation guidance from Western States Metal Roofing.
| Panel profile | Field fastening pattern | Screws per square (100 sq ft) | Extra lap / trim fasteners |
|---|---|---|---|
| 36″ corrugated (7/8″) | One screw every third corrugation in the high, 4 per screw line, lines 24″ on center | About 80 | Trim: 1 metal-to-metal screw per linear foot |
| R-Panel / PBR-Panel | 3 field screws per interior panel, 5 at panel ends, into the low | About 80 to 90 | Lap screws 1 per line, 12″ to 18″ on center |
| 7.2 Panel / Western Rib | 5 panel screws in every low, plus 1 lap screw per line | About 90 to 100 | Lap screws 12″ to 18″ on center |
| Any profile, high wind or snow | Tighten screw-line spacing toward 18″ on center | Up to about 100 | Follow the wind-uplift schedule in the panel spec |
Fastener cost per square is a Roofing Brief calculation of roughly 80 screws per square times the per-screw prices in the picks above. A ZAMAC-capped top pick at $0.10 to $0.22 per screw works out to about $8 to $18 per square, while a budget painted-head screw around $0.15 to $0.17 each lands near $12 to $14 per square. Stainless and code-approved bi-metal screws are quote-based and run higher. Screws are under 1 percent of a roof’s material cost yet the part most likely to fail first, so the cost gap between tiers is small next to the price of re-fastening a roof early.
Should metal roofing screws go in the flat or the rib?
On exposed-fastener metal roofs, the modern consensus is to drive screws in the flat, not the rib. A screw in the flat presses the EPDM washer directly against the panel and the substrate for a consistent seal, and it gives the roof more shear strength against wind. Rib mounting sheds water better because the fastener sits above the drainage plane, but it lets the panel flex around the shank, which can slot the steel and leak over time.
The flat wins on anchoring and seal consistency, which is why most manufacturer instructions for R-Panel and PBR profiles call the screws into the low. The exception is classic corrugated, where some specs still fasten in the high so the head sits out of standing water and debris. Whichever the panel calls for, correct drive depth matters more than flat versus rib: overdriving squeezes the washer out and underdriving leaves a gap, and incorrect fastener installation is the single biggest cause of metal roof leaks.
Frequently asked questions
What size screws do I need for metal roofing?
Most exposed-fastener metal panels use #9, #10, #12, or #14 screws, with #10 and #12 the usual residential and light-commercial picks. Choose a length that penetrates the wood or steel substrate by at least 3/4″ but not much more than 1″, so 1″ to 1-1/2″ is standard over wood and 2″ or longer is common through insulation or thick framing. Confirm the call-out against your specific panel and framing.
Are self-drilling or self-piercing screws better for metal roofing?
It depends on the substrate. Self-drilling screws have a fluted point that bores through steel purlins up to about 0.210″ without a pilot hole, so they suit metal-to-metal work. Self-piercing Type 17 screws pierce wood and thin sheet quickly and are better for panels going into wood purlins or for re-seating replacement screws. Using a self-piercing point on thick steel often causes point walking and stripping.
What is the best coating for metal roofing screw heads?
A molded ZAMAC or ZAC zinc-aluminum cap generally lasts longest on exposed heads because it resists red rust and will not chalk or fade like paint, even if scratched during driving. In coastal air within roughly three miles of salt water, a 304 or 316 stainless head resists corrosion best. Painted-steel heads over zinc are the budget tier and can show rust or chalking sooner.
Should you use stainless steel screws on a metal roof?
Stainless screws are worth the premium mainly in coastal or industrial corrosion zones. In salt-spray testing that simulates marine air, thin zinc-plated screws can show red rust before 500 hours while 304 or 316 stainless shows little to none, and near salt water zinc-plated fasteners can begin rusting within months. Inland, a warranty-grade ZAMAC-capped screw is usually enough at a lower cost.
How long do metal roofing screws last?
Service life depends on the head and washer, not the panel. A quality ZAMAC-capped screw with an encapsulated EPDM washer can be warranted for the life of a 40-year painted-steel roof, while the EPDM washer itself is often the first part to fail and may need attention around the 20-year mark. Budget painted-steel heads and exposed-edge washers typically show wear sooner, especially in high-UV or coastal exposure.
Can you reuse metal roofing screw holes?
You generally should not re-drive the same screw into a worn hole. Once a hole is wallowed out or the washer has failed, step up to an oversized replacement screw such as a #12 Type 17 with a Strip-Loc thread and a larger EPDM washer, which re-grips the enlarged hole and reseals over the worn seat. Simply retightening a stripped screw rarely stops the leak for long.
How many screws do I need per square of metal roofing?
Plan for about 80 metal roofing screws per square (100 square feet) on a standard 36-inch exposed-fastener panel at 24 inches on center, and up to 90 to 100 per square in high-wind or heavy-snow zones. A quick estimate is roof area in square feet times 0.80. Add lap screws at 12 to 18 inches on center for R-Panel and 7.2 profiles, plus one trim screw per linear foot, and confirm the pattern against the panel manufacturer’s schedule.
Should metal roofing screws go in the rib or the flat?
On most exposed-fastener panels the modern best practice is to fasten in the flat, because the screw presses the EPDM washer directly against the panel for a consistent seal and gives the roof more shear strength against wind. Rib mounting sheds water better but lets the panel flex around the shank, which can slot the steel and leak over time. Classic corrugated is the common exception, where some specs fasten in the high. Follow the panel maker’s pattern and set the correct drive depth either way.
Reviewed by The Roofing Brief Team. Last reviewed August 2026.