Bi-Metal Screws
Bi-Metal Hex Washer Head Self-Drilling Screw
SS304 or SS316 body welded to an SS420 drill tip, indented hex washer head with SS + EPDM washer, M4.8–M7.
M4.8SS304 or SS316
Bi-Metal Screws
Bi-Metal Solar Mounting Screw
SS304 + SS420 self-drilling screws for PV mounting rails and clamps, ceramic coated 1,000 h.
- Body
- SS304
- Tip
- SS420
- Head
- Flat countersunk or hex
- Standard
- DIN
- Coating
- Ceramic, 1,000 h
- Lead time
- 25–30 days
- Free samplesUp to 20 pcs, ships in 7 days
- Lot test reportHardness, coating, drill time
- Made to orderCustom lengths, finishes, head marks
- Export readyFOB, CFR or CIF with full documents
Overview
Solar rails are aluminium, the roof structure is steel and the system must last 25 years. Bi-metal screws give stainless durability with a tip that still drills the purlin.
Flat countersunk and hex head versions to suit rail and hook designs.
Applications
- Rooftop PV mounting
- Solar carports
- Ground-mount frames
Used in these projects
Key features
- Rated for 25-year PV service life
- Works with aluminium rails
- Countersunk for low-profile clamps
- Bulk pallets for EPC projects
Specifications
Typical values. Every dimension, hardness and coating is confirmed in writing with your quotation.
| Body | SS304 |
|---|---|
| Tip | SS420 |
| Head | Flat countersunk or hex |
| Standard | DIN |
| Coating | Ceramic, 1,000 h |
| Lead time | 25–30 days |
| Packing | Box + carton + pallet |
| MOQ | 500 kg |
| HS code | 7318.14 / 7318.12 (by type) |
Buying guide
Applies to all bi-metal screws.
304 or 316 body
A2 (304) suits inland exterior use. A4 (316) contains 2–3 % molybdenum and resists chloride pitting, so specify it within about 5 km of the sea, near pools or in chemical plants.
Tip material
SS410/SS420 tips keep some corrosion resistance; SCM435 and C1022 tips drill faster in thick steel. The tip should break through before the stainless threads engage.
Isolate dissimilar metals
On aluminium solar rails and cladding use a stainless EPDM washer or a coated screw to reduce galvanic corrosion between the fastener and the profile.
Ordering
Packing and delivery
Standard terms for this product. Tell us if your market needs something different.
PackingSmall boxes, buckets or 20–25 kg cartons on fumigated pallets; private label available.
Lead timeSamples in 7 days; production 25–35 days after deposit.
PaymentT/T 30 % deposit, 70 % against B/L copy, or L/C at sight.
ShippingFOB Shanghai or Ningbo, CFR or CIF to your port.
Questions about this product
How thick a steel section can a bi-metal screw drill?
Depending on point size, from 0.75 mm sheet up to about 6 mm structural steel. For thicker purlins we recommend a #5 point carbon screw or pre-drilling.
Are bi-metal screws magnetic?
The 304/316 body is mostly non-magnetic, while the hardened tip is magnetic. That is a quick way to confirm a bi-metal screw on site.
Do you supply mill certificates?
Yes. Each lot ships with a material test certificate covering chemistry, hardness, case depth and salt spray results.
Bi-Metal Screws
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Request for quotation
Request a quotation for Bi-Metal Solar Mounting Screw
Tell us the screw, size and quantity. A sales engineer replies within one business day with price, lead time and a sample offer.
- Emailinquiry@china-screw-factory.com
- WhatsApp+86 176 2154 1688
- Phone+86 176 2154 1688