Applications and selection
Assemblies with a matching square or suitably designed receiving hole, including wood-to-metal and fabricated connections.
Specify the square-neck dimensions and engagement, not only the thread diameter. Check the grip length and how the neck seats in the connected material.
Dimensions & technical reference
DIN 603:2017
The square neck prevents rotation in a matching hole. The cited table covers M5–M20; larger catalog inquiries require a drawing.
| Nominal size | P | dk max | k max | s max | k1 max |
|---|---|---|---|---|---|
| M5 | 0.8 | 13.55 | 3.3 | 5.48 | 4.1 |
| M6 | 1 | 16.55 | 3.88 | 6.48 | 4.6 |
| M8 | 1.25 | 20.65 | 4.88 | 8.58 | 5.6 |
| M10 | 1.5 | 24.65 | 5.38 | 10.58 | 6.6 |
| M12 | 1.75 | 30.65 | 6.95 | 12.7 | 8.75 |
| M16 | 2 | 38.8 | 8.95 | 16.7 | 12.9 |
| M20 | 2.5 | 46.8 | 11.05 | 20.84 | 15.9 |
Dimensional source: 164580 · DIN 603:2017 ↗. “—” means no value listed for this combination. P is thread pitch; min / max are dimensional limits. The selection above is not the full standard or a stock list.
Catalog inquiry range: M5 - M24. Availability, lengths, grades and finishes are confirmed by quotation. Sizes outside the cited reference table require the applicable standard dimensions or an approved drawing. Quote the exact standard and edition; DIN, ISO and U.S. references are not automatically interchangeable.
Materials, surface finishes and standards
Materials for this series: Carbon Steel, Stainless Steel. Surface finishes: Black Oxide, Zinc Plated, HDG. Compatibility between the grade, finish and operating environment needs to be confirmed.
For titanium, nickel alloy or other non-ferrous requirements, include the exact material grade and drawing. Required mechanical properties, inspection documents and traceability should be stated in the inquiry.
Related U.S. dimensional reference for round-head and square-neck bolt forms. Confirm neck geometry, head dimensions and thread system. Standards from different systems can vary in dimensions, threads, product scope and test requirements. Confirm the exact designation and edition in the quotation.
Ordering standard
DIN 603:2017
United States references for a separate inquiry: ASME B18.5 (inch). Confirm the exact form, thread system and drawing before quoting.
What to send for a quotation
- Carriage Bolts or your part number, with the relevant standard and edition.
- Exact dimensions, thread details, quantity and any critical tolerances.
- Material grade, surface finish, inspection requirements and delivery destination.
- For customization, a drawing revision and a description of the mating assembly.
Common questions about carriage bolts
Does a carriage bolt fit any round hole?
The square neck needs a suitable receiving geometry. Confirm the hole or material engagement against the joint design before ordering.
Can I request a size or material outside this listing?
Yes. Send the required dimensions and exact material grade for review. A quotation is needed to confirm feasibility, price and lead time.