DIN 6334 Hex Coupling Nuts (Long Hex Nuts)
DIN 6334 hex coupling nuts — the long hex nut at roughly 1.5 × thread diameter length, M6 to M36 — with the full collected 14-size table: pitch, across-flats, nut length, across-corners and the source's reference mass per 1000 units.
Last updated: 2026-11
Specifications
DIN 6334 is the long hex nut — sometimes called an extension or coupling nut — with a length of about 1.5 × the thread diameter, roughly 50% more thread engagement than a standard hex nut. Its working roles follow from that engagement: joining two threaded rods end-to-end (the classic rod-coupling use), adding make-up length on long stud runs, and anchoring threaded rod into fixtures where the extra engagement carries pull-out load. The collected table runs M6 to M36 and includes the source's reference mass per 1000 units — a useful shipping-weight figure, reproduced as printed. Across-flats matches the ordinary hex nut series, so the same wrench serves both. Because the nut is plain and long, it pairs naturally with threaded rod (the DIN 975/DIN 976 pages on this site cover the rod series); where vibration is present, add a locking element rather than relying on engagement alone. Material and finish are not part of the collected table and follow the quotation.
| Standard | DIN 6334 — hexagon long nuts (coupling nuts) |
|---|---|
| Series | M6 – M36 (14 sizes tabulated) |
| Tabulated geometry | Per size: pitch P, across-flats s, nut length L, across-corners e, approximate mass per 1000 units (kg, printed by the source as a reference figure) |
| Nut form | Plain hex, length ≈ 1.5 × thread diameter — extended thread engagement |
| Family note | Pairs with the DIN 975 / DIN 976 threaded-rod series for rod coupling and stud extensions |
| Materials / strength | Not tabulated by the collected specification — per RFQ (material and finish per drawing callout) |
| Nominal thread | P — Pitch | s | L | e | per 1000 units ≈ kg |
|---|---|---|---|---|---|
| M6 | 1 | 10 | 18 | 11.05 | 7 |
| M8 | 1.25 | 13 | 24 | 14.38 | 18 |
| M10 | 1.5 | 17 | 30 | 18.9 | 42 |
| M12 | 1.75 | 19 | 36 | 21.1 | 63 |
| M14 | 2 | 22 | 42 | 24.49 | 95.5 |
| M16 | 2 | 24 | 48 | 26.75 | 122 |
| M18 | 2.5 | 27 | 54 | 29.56 | 140 |
| M20 | 2.5 | 30 | 60 | 33.53 | 240 |
| M22 | 2.5 | 32 | 66 | 35.03 | 300 |
| M24 | 3 | 36 | 72 | 39.98 | 412 |
| M27 | 3 | 41 | 81 | 45.2 | 608 |
| M30 | 3.5 | 46 | 90 | 50.85 | 825 |
| M33 | 3.5 | 50 | 99 | 55.37 | 1100 |
| M36 | 4 | 55 | 108 | 60.79 | 1470 |
Materials
- Material and finish specified per RFQ — the collected specification table covers geometry only
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 6334 Hex Coupling Nuts (Long Hex Nuts)) 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
How much more engagement does a DIN 6334 coupling nut give than a standard hex nut?
Its length is about 1.5 × thread diameter against roughly 0.8–0.9 × for a style 1 nut — close to 75% more engaged thread. That engagement is why it anchors threaded rod so well, but note the extra length does not change the thread strength class: pull-out capacity still depends on the material pair. Check the L column in the table against the run-up your rod-to-rod or rod-to-fixture joint needs, and confirm material pairing at quotation.
What is the MOQ and lead time for this nut type?
The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common diameters in this nut type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
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