Key specifications
| Sizes | ST3.5 to ST6.3 |
|---|---|
| Lengths | About 25 mm to 150 mm for winged types |
| Drives | Cross recess, square or Torx |
| Materials | Case-hardened carbon steel; stainless 410 on request |
| Finishes | Zinc plated, ceramic-type coatings |
| Uses | Timber decking, plywood and fibre-cement board to steel |
Made to order in China and shipped FOB or CIF from Tianjin, Ningbo, Shanghai or Shenzhen. Sizes, grades and finishes outside this list can be quoted.
Dimension drawing
ISO 15482 dimensions and drilling range
| Size | Head Ø dk max (mm) | Head height k max (mm) | Recess no. | Drilling range (mm) | Inquiry |
|---|---|---|---|---|---|
| ST3.5 | 7.3 | 2.35 | 2 | 0.7–2.25 | Quote this size |
| ST4.2 | 8.4 | 2.6 | 2 | 1.75–3 | Quote this size |
| ST4.8 | 10.4 | 2.8 | 2 | 1.75–4.4 | Quote this size |
| ST5.5 | 11.5 | 3.0 | 3 | 1.75–5.25 | Quote this size |
| ST6.3 | 12.6 | 3.15 | 3 | 2–6 | Quote this size |
Getting the length right
- Length = timber or board thickness + steel thickness + enough thread to engage the steel fully.
- The wings must clear the full timber thickness before they reach the steel; state the timber thickness so the wing position matches.
- Thick timber over thick steel may need a longer drill point; send both thicknesses.
- Countersunk heads need a nib or rib under the head to self-countersink in hardwood; ask if you need that feature.
Packing, shipping and documents
| MOQ | 500 pcs per specification; mixed sizes can be combined on one order |
|---|---|
| Lead time | 10–15 days for stock items, 25–30 days for production orders, confirmed in the quotation |
| Export packing | Inner boxes or bags labelled by size, export cartons, then palletized and stretch-wrapped; buyer labels and barcodes on request |
| Shipping ports | Tianjin, Ningbo, Shanghai, Shenzhen |
| Incoterms | EXW, FOB, CFR, CIF, DAP, DDP on request |
| HS code reference | HS 7318.14 (self-tapping screws) is the usual heading for self-drilling screws. Confirm the final code with your customs broker. |
| Certificate of origin | ACFTA Form E available on request for buyers in ASEAN countries such as Malaysia, Indonesia, Vietnam and the Philippines |
| Order documents | Commercial invoice, packing list and inspection records agreed in the quotation |
What to include in your RFQ
- Size and length
- Timber / board thickness and steel thickness
- Drive and head features (ribs, nibs)
- Coating
- Packing, quantity per size, destination
Frequently asked questions
What are the wings on a self-drilling screw for?
They ream a hole through timber slightly larger than the thread, then snap off at the steel. This stops the timber riding up the thread and leaves a tight joint.
Can I use winged screws in steel only?
They are designed for timber or board over steel. For steel-to-steel, use pan or hex washer head self-drilling screws.
Which standard covers countersunk self-drilling screws?
ISO 15482 covers the cross-recessed countersunk type. Winged versions are made to supplier drawings based on it.
What is the MOQ?
Reference MOQ is 500 pcs per specification. Standard sizes typically ship in 10–15 days and made-to-order sizes in 25–30 days, confirmed with each quotation. We reply to every RFQ within 2 working hours.
Sources for technical review