# Acorn (domed cap) nuts, DIN 1587 high type: M4–M24 dome diameter, overall height, across flats, thread depth

> What are the dimensions of a DIN 1587 acorn nut, and how tall is an M8 domed cap nut?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: fasten.it's DIN 1587 table (07/2014) cross-checked against Westfield Fasteners' DIN 1587 table (same dk, h, s, t, e on M4 to M24; m differs, see notes); numbers only
- Page: https://xemstudio.com/objects/acorn-cap-nuts-din-1587/ · JSON: https://xemstudio.com/api/geometry?object=acorn-cap-nuts-din-1587 · Plain text: https://xemstudio.com/objects/acorn-cap-nuts-din-1587/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no tolerance added.

## Notes

- Columns (mm): P pitch; dk max, read as the dome diameter; h overall height (nominal = max); m max, read as the thread / body height; s width across flats (nominal = max; values in brackets are the alternative wrench widths the page prints for M10, M12, M14 and M22); e across corners (min); t min / max; x or g2 as printed on the right (x max for M4 to M10, g2 max for M12 and larger). The letters are the ones the pages print; fasten.it does not define them. Westfield's table (da, dk, dw, e, x, g2, h, m, r, s, t, w) agrees with fasten.it on dk, h, s, t and e (grade A minimum) for every size M4 to M24. The two disagree on m: fasten.it's coarse-thread m max is 10 for M10 (11.7 M12), Westfield prints m min 8.00 / max 7.64 for M10 (10.00 / 9.64 for M12), which equal fasten.it's fine-thread m (8.0, 10.0); the coarse values shown are fasten.it's and m is uncertain.
- fasten.it also has a fine-thread table (M8x1 to M24x2) with the same dk, h and s but smaller m (e.g. M10x1.25: m 8.0 against 10.0 coarse); it is not reproduced here. fasten.it's M22x1.5 row prints t min 25.58 against 28.58 for M22x2, and the M27 and M30 coarse rows print fewer values than the columns, so they are left out. Grade A and B minimum figures are in Westfield's table (e.g. M8 e min 14.38 for grade A, 14.20 max for grade B).
- No file: the dome profile (the radius r is only an auxiliary dimension) and the thread depth do not define a full solid in the sources read. McMaster-Carr sells acorn and cap nuts with per-part STEP; its metric acorn and cap-nut categories are linked, not copied. Nylon-insert nuts (domed or hex): nylon-insert-lock-nuts-iso-7040-din-985.

## Sizes

| thread | P (mm) | dk max | h (nom = max) | m max | s (nom = max) | e min | t min / max | x or g2 max |
|---|---|---|---|---|---|---|---|---|
| M4 | 0.7 | 6.5 | 8 | 4.1 | 7 | 7.66 | 5.26 / 5.74 | x 1.4 |
| M5 | 0.8 | 7.5 | 10 | 5.4 | 8 | 8.79 | 7.21 / 7.79 | x 1.6 |
| M6 | 1 | 9.5 | 12 | 6 | 10 | 11.05 | 7.71 / 8.29 | x 2 |
| M8 | 1.25 | 12.5 | 15 | 8.5 | 13 | 14.38 | 10.7 / 11.4 | x 2.5 |
| M10 | 1.5 | 15 | 18 | 10 | 16 (17) | 17.77 | 12.7 / 13.4 | x 3 |
| M12 | 1.75 | 17 | 22 | 11.7 | 18 (19) | 20.03 | 15.7 / 16.4 | g 6.4 |
| M14 | 2 | 20 | 25 | 13 | 21 (22) | 23.35 | 17.7 / 18.4 | g 7.3 |
| M16 | 2 | 23 | 28 | 16 | 24 | 26.75 | 20.6 / 21.4 | g 7.3 |
| M18 | 2.5 | 26 | 32 | 18.7 | 27 | 29.56 | 24.6 / 25.4 | g 9.3 |
| M20 | 2.5 | 28 | 34 | 19.7 | 30 | 32.95 | 25.6 / 26.4 | g 9.3 |
| M22 | 2.5 | 33 | 39 | 22.7 | 32 (34) | 37.29 | 28.6 / 29.4 | g 9.3 |
| M24 | 3 | 34 | 42 | 23.5 | 36 | 39.55 | 30.5 / 31.5 | g 10.7 |

## Where the files are

- fasten.it: [DIN 1587 hexagon domed cap nuts, high type (07/2014): d, P, da, dk, dw, e, x, g2, h, m, r, s, t, w; coarse M4 to M30 and fine thread](https://fasten.it/norms/norm/din_1587) — web — Reference page; numbers only. The page does not define the column letters
- Westfield Fasteners: [DIN 1587 dome nuts M4 to M24: da, dk, dw, e, h, m, r, s, t, w (Table 1)](https://westfieldfasteners.co.uk/Standards/Nut-Dome-M.pdf) — web — Publisher's page; dimensions are facts
- McMaster-Carr: [Metric acorn nuts (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/metric-acorn-nuts) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)
- McMaster-Carr: [Metric cap nuts (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/metric-cap-nuts/) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Questions

**How tall is an M8 acorn nut?**

15 mm overall (DIN 1587 high type), 13 mm across flats, dome diameter 12.5 mm max (fasten.it; Westfield agrees).

**What wrench size is an M10 acorn nut?**

16 mm, with 17 mm printed as an alternative on fasten.it (the s = 17 column in brackets).

## Fits with

- [Hex nuts, M2–M8 (ISO 4032)](https://xemstudio.com/objects/hex-nuts-metric/)
- [Hex nuts, M10 to M24 (ISO 4032 / DIN 934)](https://xemstudio.com/objects/hex-nuts-metric-m10-m24/)
- [Nylon-insert lock nuts (nyloc), ISO 7040 and DIN 985, M3–M36: width across flats, height, bearing diameter + M10–M30 envelope files](https://xemstudio.com/objects/nylon-insert-lock-nuts-iso-7040-din-985/)
- [Hex flange nuts, DIN 6923: M3–M20 across flats, flange diameter, height, flange thickness + M5–M16 envelope files](https://xemstudio.com/objects/flange-nuts-din-6923/)
- [Square nuts, DIN 557: M5–M20 width across flats, thickness, corner distance + 8 envelope files](https://xemstudio.com/objects/square-nuts-din-557/)