DIN 7504 Self-Drilling Screws — Tek Fastener for Marine & Steel
Self-Drilling Screw — DIN 7504 Tek Screw
Self-drilling screws (also known as tek screws) combine drilling and tapping in a single operation, eliminating the need for pre-drilling when fastening metal sheets. Manufactured per DIN 7504 series standards, sinofastener supplies a complete range of self-drilling self-tapping screws in carbon steel, stainless steel A2/A4, with zinc plated or hot-dip galvanized coatings — covering sizes from 2.9 mm to 6.3 mm shank diameter and 6.5 mm to 75 mm length. Products can be supplied with material certificates and are available for third-party inspection.
What Is a Self-Drilling Screw?
Aself-drilling screw features a drill-shaped point (numbered 1 through 5 per DIN 7504) that acts as a built-in drill bit. Unlike standard self-tapping screws that require a pre-drilled pilot hole, self-drilling screws penetrate the base material directly. The drill point geometry determines the maximum sheet thickness the screw can penetrate without pre-drilling:
| Point No. | Max Penetration (mm) | Typical Use |
|---|---|---|
| #1 | Up to 0.9 | Thin sheet metal (HVAC ducts, light gauge framing) |
| #2 | Up to 2.5 | Light structural steel, metal partitions |
| #3 | Up to 5.0 | Medium structural steel, ship equipment brackets |
| #4 | Up to 8.0 | Heavy structural steel, deck plate |
| #5 | Up to 12.5 | Thick steel plate, hull attachment points |
Marine Applications
Note: Applications listed below are based on typical industry practice for self-drilling screws in marine and offshore environments, per DIN 7504 series general guidelines.
| Application | Typical Specification | Material / Coating |
|---|---|---|
| HVAC duct mounting in engine room | 4.8 × 19 mm, hex washer head, Point #2 | Zinc plated carbon steel |
| Cabin interior partition framing | 4.2 × 25 mm, bugle head, Point #1 | Phosphate or zinc plated |
| Deck equipment bracket fastening | 5.5 × 32 mm, hex washer head, Point #3 | Hot-dip galvanized or A2 stainless |
| Pipe support and hanger assembly | 4.8 × 25 mm, pan head, Point #2 | Zinc plated or A4 stainless |
| Superstructure cladding panel | 5.5 × 25 mm, hex washer head, Point #2 | A2 stainless steel (AISI 304) |
| Outfitting and non-structural attachment | 4.2 × 19 mm, countersunk head, Point #1 | Zinc plated carbon steel |
Specifications & Materials
| Parameter | Range | Standard Reference |
|---|---|---|
| Standard | DIN 7504 series | DIN 7504-1/2/3/4/5/7 |
| Shank Diameter | 2.9 – 6.3 mm | DIN 7504 |
| Length Range | 6.5 – 75 mm | DIN 7504 |
| Head Types | Hex washer / Pan / Countersunk / Bugle | DIN 7504-1 (hex) / -2 (CSK) / -3 (pan) / -4 (bugle) |
| Drive Type | Hex socket (H) / Phillips (PH) / Pozidriv (PZ) | DIN 7504 |
| Drill Point | #1 – #5 (per DIN 7504) | DIN 7504 Annex |
| Material Grade | Case-hardened steel / C1022; A2 (AISI 304); A4 (AISI 316) | ISO 4042 / DIN 7504 |
| Surface Treatment | Zinc plated / Hot-dip galvanized / Phosphate / Plain stainless | ISO 4042 / ISO 10683 |
| Max Penetration Thickness | 0.9 – 12.5 mm (depends on point number) | DIN 7504 |
| Fire Reaction Class | Class A1 (steel, uncoated) | EN 13501-1 |
Why Choose sinofastener for Self-Drilling Screws?
- EN 14399 / EN 15048 dual-certified manufacturer — China's first
- Annual capacity 50,000 tons, full range across GB / DIN / EN / ISO / ASTM / BS
- Integrated manufacturing & trade — direct factory pricing, no middleman markup
- Material certificates available; third-party inspection supported on request
Standards Reference
- DIN 7504-1 — Hexagon head self-drilling screws with hex washer
- DIN 7504-2 — Countersunk head self-drilling screws
- DIN 7504-3 — Raised countersunk head self-drilling screws
- DIN 7504-4 — Pan head self-drilling screws
- DIN 7504-5 — Countersunk head self-drilling screws with Phillips recess
- DIN 7504-7 — Hexagon head self-drilling screws (heavy duty)
- ISO 4042 — Electroplated coatings on fasteners
- ISO 10683 — Hot-dip galvanized coatings on fasteners
FAQ
Q: What is the difference between self-drilling and self-tapping screws?
A: Self-drilling screws have a drill-shaped point (DIN 7504) that eliminates the need for a pre-drilled pilot hole. Self-tapping screws require a pre-drilled hole; they cut their own thread but do not drill through the base material.
Q: How do I choose the correct drill point number?
A: The point number (#1 to #5) corresponds to the maximum sheet thickness the screw can penetrate without pre-drilling. #1 suits thin sheets up to 0.9 mm; #5 handles up to 12.5 mm. Per DIN 7504, select the lowest point number that covers your sheet thickness for optimal performance.
Q: Which surface treatment is recommended for marine environments?
A: For marine applications, hot-dip galvanized (per ISO 10683) or stainless steel A2/A4 (AISI 304/316) is recommended. Zinc plating per ISO 4042 is suitable for protected indoor environments only.
Q: Can you supply self-drilling screws with specific drill point and head combinations?
A: Yes. We supply the full DIN 7504 range — any combination of head type (hex washer, pan, countersunk, bugle), material grade (carbon steel, A2, A4), surface treatment (zinc plated, HDG, phosphate, plain stainless), and drill point (#1 to #5) is available.
Contact Us
Email: sales@sinofastener.com
Website: www.zlfastener.com | www.sinofastener.com (Main)
