DIN 7504-K Self-Drilling Screws (Hexagon Head with Serration)
Self-drilling screws per DIN 7504 form K — hexagon head with serration, zinc plated steel — running Ø 3.5 to 6.3 mm × length 13 to 140 mm, the widest collected drilling ladder of the DIN 7504 forms, with max drilling capacity 2–6 mm and per-length clamping range.
Last updated: 2026-11
Specifications
The DIN 7504-K is the hex-head member of the self-drilling family: a serrated hexagon driven by a socket or nut-runner that takes higher installation torque than a recess-driven head, which is why metal-roofing and framing crews run it with speed tools. The collected line-page table is also the widest of the four DIN 7504 forms — Ø 3.5 through 6.3 mm with lengths from 13 up to 140 mm — and it extends the drilling-capacity ladder one step past the recessed forms: 2 mm at Ø 3.5/3.9, 3 mm at 4.2, 4 mm at 4.8, 5 mm at 5.5 and 6 mm at 6.3, with clamping ranges from 4 mm at the shortest rows to 129 mm at Ø 6.3 × 140. At Ø 4.8 the ladder runs thirteen to seventy millimetres (clamping 4–61 mm); at Ø 6.3 it runs nineteen to one hundred forty (clamping 8–129 mm). The drive column prints socket sizes — N°5.5 at Ø 3.5/3.9, N°7 at 4.2, N°8 at 4.8/5.5, N°10 at 6.3. As with every DIN 7504 form, the length must be chosen so the point clears the total steel within its drilling capacity and the thread engages inside the clamping range. The collected tables are metric; the inch TEK point-number series is not carried by this source and is not stated here.
| Standard | DIN 7504 form K — self-drilling screw, hexagon head with serration |
|---|---|
| Size range | Ø 3.5 – 6.3 mm × length 13 – 140 mm (collected table) |
| Max drilling capacity | 2 mm (Ø 3.5/3.9) · 3 mm (Ø 4.2) · 4 mm (Ø 4.8) · 5 mm (Ø 5.5) · 6 mm (Ø 6.3) |
| Clamping range | 4 – 129 mm across the collected length ladder, per size and length |
| Drive | Socket sizes as printed: N°5.5 (Ø 3.5/3.9), N°7 (Ø 4.2), N°8 (Ø 4.8/5.5), N°10 (Ø 6.3) |
| Finish | Zinc plated steel, as printed on the collected line page |
| Case hardness | Rockwell C52-58 minimum (C), per the collected self-drilling hardness table |
| Core hardness (after tempering) | Rockwell C32-40, per the collected self-drilling hardness table |
| Material | AISI 1016-1024 or equivalent steel, per the collected self-drilling hardness table |
| Materials | Zinc plated carbon steel (case hardened per the collected hardness row); stainless and other finishes confirmed at quotation |
| Ø — screw diameter (mm) | l — length (mm) | Max drilling capacity (mm) | Clamping range (mm) | Drive bit (as printed) |
|---|---|---|---|---|
| 3.5 | 13 | 2 | 8 | N°5.5 |
| 3.5 | 16 | 2 | 11 | N°5.5 |
| 3.5 | 19 | 2 | 14 | N°5.5 |
| 3.5 | 25 | 2 | 20 | N°5.5 |
| 3.9 | 13 | 2 | 7 | N°5.5 |
| 3.9 | 16 | 2 | 10 | N°5.5 |
| 3.9 | 19 | 2 | 14 | N°5.5 |
| 3.9 | 22 | 2 | 16 | N°5.5 |
| 3.9 | 25 | 2 | 19 | N°5.5 |
| 4.2 | 13 | 3 | 6 | N°7 |
| 4.2 | 16 | 3 | 9 | N°7 |
| 4.2 | 19 | 3 | 12 | N°7 |
| 4.2 | 22 | 3 | 15 | N°7 |
| 4.2 | 25 | 3 | 18 | N°7 |
| 4.2 | 32 | 3 | 25 | N°7 |
| 4.2 | 38 | 3 | 31 | N°7 |
| 4.8 | 13 | 4 | 4 | N°8 |
| 4.8 | 16 | 4 | 7 | N°8 |
| 4.8 | 19 | 4 | 10 | N°8 |
| 4.8 | 22 | 4 | 13 | N°8 |
| 4.8 | 25 | 4 | 16 | N°8 |
| 4.8 | 32 | 4 | 23 | N°8 |
| 4.8 | 38 | 4 | 29 | N°8 |
| 4.8 | 45 | 4 | 36 | N°8 |
| 4.8 | 50 | 4 | 41 | N°8 |
| 4.8 | 60 | 4 | 51 | N°8 |
| 4.8 | 70 | 4 | 61 | N°8 |
| 5.5 | 19 | 5 | 9 | N°8 |
| 5.5 | 22 | 5 | 12 | N°8 |
| 5.5 | 25 | 5 | 15 | N°8 |
| 5.5 | 32 | 5 | 22 | N°8 |
| 5.5 | 38 | 5 | 28 | N°8 |
| 5.5 | 45 | 5 | 35 | N°8 |
| 5.5 | 50 | 5 | 40 | N°8 |
| 5.5 | 60 | 5 | 50 | N°8 |
| 5.5 | 70 | 5 | 60 | N°8 |
| 5.5 | 75 | 5 | 65 | N°8 |
| 6.3 | 19 | 6 | 8 | N°10 |
| 6.3 | 22 | 6 | 11 | N°10 |
| 6.3 | 25 | 6 | 14 | N°10 |
| 6.3 | 32 | 6 | 21 | N°10 |
| 6.3 | 38 | 6 | 27 | N°10 |
| 6.3 | 50 | 6 | 39 | N°10 |
| 6.3 | 60 | 6 | 49 | N°10 |
| 6.3 | 70 | 6 | 59 | N°10 |
| 6.3 | 80 | 6 | 69 | N°10 |
| 6.3 | 100 | 6 | 89 | N°10 |
| 6.3 | 120 | 6 | 109 | N°10 |
| 6.3 | 140 | 6 | 129 | N°10 |
Materials
- Zinc plated carbon steel (case hardened per the collected hardness row); stainless and other finishes confirmed at quotation
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (DIN 7504-K Self-Drilling Screws (Hexagon Head with Serration)) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
What does the serration under the hex head do?
It locks the socket onto the head and lets the drive transmit higher torque without cam-out — the reason hex-head self-drilling screws are installed with impact guns and mag drills on framing and cladding jobs. The serrations bite into the socket face as torque rises, so the driving force goes into the drill point and thread instead of slipping out of the head. The collected table pairs each diameter with a socket size (N°5.5/N°7/N°8/N°10); driving with the matched socket protects the zinc plating and the head corners.
Why does the 7504-K ladder matter for thicker steel sections?
It is the only collected DIN 7504 form that reaches a 6 mm drilling capacity — at Ø 6.3 mm — and it runs lengths to 140 mm with clamping ranges to 129 mm. On built-up sections that total more than 5 mm of steel, the 6.3 diameter is the collected option; below that, the ladder still has to respect the same rule: total drilled thickness within the capacity for the diameter, thread engagement inside the printed clamping range. Confirm both figures against the actual layer stack before committing a length, since a point that is asked to drill past its capacity is the classic site failure.
What is the MOQ and lead time for these self-drilling screws?
Minimum order quantity is 10,000 pieces per item. Stocked sizes ship in 3–7 days; non-stock diameters, lengths or finishes are quoted with a confirmed schedule. Self-drilling screws in the common DIN 7504 sizes are widely stocked — confirm the exact schedule against quantity and size mix at quotation.
What should an RFQ for self-drilling (TEK) screws state?
State the standard designation and form letter (for example DIN 7504 N or DIN 7504 K), screw diameter and length, the total thickness and type of the metal being drilled through and clamped, head form and drive, finish (for example zinc plated), required certificates such as a mill test report per EN 10204 3.1, and quantity per size — plus destination country.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support