Applications and selection
Machinery, fixtures and equipment assemblies where an internal-hex drive suits the available tool access.
Check the head diameter, head height, socket size and under-head length. A countersunk or button head is a different geometry and should not be substituted without checking the drawing.
Dimensions & technical reference
DIN 912:1983
Cylindrical head; internal hexagon drive. Specify ISO 4762 separately when required.
| Nominal size | P | dk max | k max | s nominal | t min |
|---|---|---|---|---|---|
| M1.4 | 0.3 | 2.6 | 1.4 | 1.3 | 0.6 |
| M1.6 | 0.35 | 3 | 1.6 | 1.5 | 0.7 |
| M2 | 0.4 | 3.8 | 2 | 1.5 | 1 |
| M2.5 | 0.45 | 4.5 | 2.5 | 2 | 1.1 |
| M3 | 0.5 | 5.5 | 3 | 2.5 | 1.3 |
| M4 | 0.7 | 7 | 4 | 3 | 2 |
| M5 | 0.8 | 8.5 | 5 | 4 | 2.5 |
| M6 | 1 | 10 | 6 | 5 | 3 |
| M8 | 1.25 | 13 | 8 | 6 | 4 |
| M10 | 1.5 | 16 | 10 | 8 | 5 |
| M12 | 1.75 | 18 | 12 | 10 | 6 |
| (M14) | 2 | 21 | 14 | 12 | 7 |
| M16 | 2 | 24 | 16 | 14 | 8 |
| (M18) | 2.5 | 27 | 18 | 14 | 9 |
| M20 | 2.5 | 30 | 20 | 17 | 10 |
| (M22) | 2.5 | 33 | 22 | 17 | 11 |
| M24 | 3 | 36 | 24 | 19 | 12 |
| (M27) | 3 | 40 | 27 | 19 | 13.5 |
| M30 | 3.5 | 45 | 30 | 22 | 15.5 |
| (M33) | 3.5 | 50 | 33 | 24 | 18 |
| M36 | 4 | 54 | 36 | 27 | 19 |
Dimensional source: 164580 · DIN 912:1983 ↗. “—” 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: M3 - M64. 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, Alloy Steel, Aluminum. Surface finishes: Black Oxide, Zinc Plated, HDG, PTFE, Dacromet, Nickel, Chrome. 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.
Socket-head dimensions must be checked against the selected inch or metric system; these references are not a statement of dimensional interchangeability with DIN 912. 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 912:1983; ISO 4762 available by specified edition
United States references for a separate inquiry: ASME B18.3 (inch); ASME B18.3.1M (metric reference). Confirm the exact form, thread system and drawing before quoting.
What to send for a quotation
- Socket head cap 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 socket head cap bolts
What is the difference between a socket head cap bolt and a hex bolt?
The socket head uses an internal drive, while an external hex head is driven from the outside. Available tool access and head clearance help determine the appropriate style.
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.