DIN 605 Flat Countersunk Square Neck Bolts (Long Square)
Flat countersunk square-neck (coach) bolts to DIN 605 — long square neck, shank M6 to M10 in the collected ladder with head/shank/square-neck min-max rows and the grip-based thread-length bands.
Last updated: 2026-11
Specifications
DIN 605 is the long-square-neck flat countersunk bolt — the coach-bolt form where the round head seats flush in a countersunk hole and the square neck under the head turns with the bolt so a single wrench acts on the nut only. The long square suits thicker timber and clamp-up depth: the neck engages more material between the countersink and the nut face. The collected ladder covers M6 to M10 with min/max rows for the countersunk head diameter d k (16.55 → 24.65 mm max), shank d s, head height k and the neck dimension s (label as printed — the collected page carries no legend for it). Thread length follows the grip bands (L≤125 / 125＜L≤200 / L＞200). Lengths themselves are not tabulated by the collected specification — quote diameter × length off your drawing. Material, property class and finish are not printed by the source — per RFQ (state bare, galvanized or the timber-joint coating at quotation).
| Standard | DIN 605 — flat countersunk square neck bolts, long square |
|---|---|
| Size range | M6 – M10 in the collected ladder |
| Head diameter | d k: 15.45 – 24.65 mm min/max across the ladder |
| Head height | k: min/max per size as printed |
| Neck dimension | s: min/max per size (6.48 → 10.58 mm max) — label as printed, no legend on the collected page |
| Thread length | b by grip: L≤125 / 125＜L≤200 / L＞200 rows per size |
| Lengths | Not tabulated by the collected specification — quote diameter × length per drawing |
| Material / finish | Not tabulated by the collected specification — per RFQ |
| Attribute | M6 | M8 | M10 |
|---|---|---|---|
| P — Pitch | 1 | 1.25 | 1.5 |
| b — L≤125 | 18 | 22 | 26 |
| b — 125＜L≤200 | 24 | 28 | 32 |
| b — L＞200 | / | 41 | 45 |
| d k — max | 16.55 | 20.65 | 24.65 |
| d k — min | 15.45 | 19.35 | 23.35 |
| d s — max | 6 | 8 | 10 |
| d s — min | 5.52 | 7.42 | 9.42 |
| k — max | 7.45 | 9.45 | 11.55 |
| k — min | 6.55 | 8.55 | 9.45 |
| s — max | 6.48 | 8.58 | 10.58 |
| s — min | 5.52 | 7.42 | 9.42 |
- Row 4 (b — L＞200): The source prints "/" for the L＞200 thread length on M6 — carried verbatim.
- Row 10 (k — min): The source's k min ladder (6.55 → 8.55 → 9.45) drops from a 1 mm to a 3 mm step at M10 — transcribed verbatim; verify against DIN 605 itself before using this cell.
- Row 12 (s — min): The s label carries no legend on the collected page — carried verbatim as printed; disambiguate against DIN 605 itself.
Materials
- Material and finish specified per RFQ — square-neck bolts are typically supplied bare steel or hot-dip galvanized for timber and general construction; state the joint and coating 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 605 Flat Countersunk Square Neck Bolts (Long Square)) 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 1,000–10,000 pieces depending on size. Stock items run 3–7 days. High-strength and custom parts run 15–25 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
DIN 605 or DIN 608 — long square or short square?
By the clamped thickness. Both are flat-countersunk square-neck bolts; the difference in the collected tables is the neck length and, with it, the size coverage — DIN 605 (long square) is tabulated M6 to M10, DIN 608 (short square) at M10 and M12. A long square turns with the bolt through more material, which is what a deep timber pack-up needs; a short square suits thinner clamps where the neck must not punch through the far face before the countersink seats. Compare the s (square side) and head d k rows across both pages, then choose by the drawn neck length — the collected tables do not tabulate the neck length itself, so confirm the square dimension on the RFQ.
Related knowledge
- What Bolt Property Classes 8.8, 10.9 and 12.9 Encode — and When High Strength Stops Being the Right Choice
- Bolt Grade Selection: ISO 898-1 8.8/10.9/12.9 vs ASTM A307 and A325
- 8.8 vs 10.9 vs 12.9 Bolts: Strength, Hardness and Cost — What the Evidence Settles
- Calculating Bolt Preload and Clamp Force: Torque, Friction and Tightening Method
- How to Determine Tightening Torque and Choose a Tightening Method for a Bolted Joint
- Fastener Failure Modes: Which Fatigue, Creep and SCC Controls the Evidence Supports
- Hydrogen Embrittlement in High-Strength Bolts: Which Grades Need Controls, Which Coatings and Baking Schedules Are Acceptable, and What to Require Before the RFQ
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