# Shoulder screws ISO 7379 (metric): shoulder Ø, thread, head size, hex key, thread length, M5 to M20

> What are the dimensions of an ISO 7379 metric shoulder screw: shoulder diameter, thread, head diameter and height, hex key size and thread length?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: ISO 7379:1983 sample pages, fasten.it, Ganter Norm and McMaster part mirrors; disagreements are listed rather than averaged; McMaster-Carr linked for CAD
- Page: https://xemstudio.com/objects/shoulder-screws-iso-7379/ · JSON: https://xemstudio.com/api/geometry?object=shoulder-screws-iso-7379 · Plain text: https://xemstudio.com/objects/shoulder-screws-iso-7379/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 printing tolerance added.

## Notes

- ISO 7379 is the hexagon socket head shoulder screw: a hardened, ground shoulder of diameter d1 that acts as a bearing surface or pivot, then a shorter thread. The shoulder length l1 is the dimension you choose; thread size, head and key are fixed per shoulder diameter. Pitches are ISO coarse. Preferred l1 in the 1983 edition: 10, 12, 16, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 120 mm; shoulder tolerance f9 or h8 depending on the supplier.
- Where sources agree: head diameter and hex key size for all seven sizes (ISO 7379:1983 sample, fasten.it, Ganter Norm); shoulder diameter for M6, M8, M12 and M16 (8, 10, 16, 20); McMaster-Carr part mirrors match the 1983 sample for M5 (6 mm shoulder, head 10 × 5, 3 mm key) and M10 (13 mm shoulder, 10 mm head height, 6 mm key).
- Where sources disagree: shoulder diameter M5: 6 mm (ISO sample, Ganter, McMaster mirror) vs 6.5 mm (fasten.it); M10: 13 mm (ISO sample, fasten.it, McMaster mirror) vs 12 mm (Ganter, Accu Components); M20: 25 mm (ISO sample, fasten.it) vs 24 mm (Ganter). The table and files use the 1983 sample's values (6, 13, 25), the alternates are shown in brackets. Head height: the 1983 sample and the two McMaster mirrors give 5 (M5) and 10 (M10); fasten.it prints smaller maxima (4.5 to 16, in brackets); Accu lists 8.9 for M10; a Zoro M16 listing shows 14. M10 head diameter is 18 in the sample, fasten.it, Ganter and Accu but 19 on the McMaster mirror. If head height or the M10 / M5 / M20 shoulder matters, measure your part.
- Thread length b is fasten.it's maximum (corroborated by Accu: 16.4 for M10; McMaster mirrors 10 for M5, 16 for M10; Zoro 22 for M16); the socket depth t is fasten.it's minimum and has no second source. Shoulder length ranges differ between fasten.it and Ganter, so both are shown; Ganter also lists M3 (4 mm shoulder) and M4 (5 mm), noted there as not in the official ISO sheet, which are not used.
- Files: seven shoulder screws, one per thread size at an example shoulder length (40 mm; 50 mm for M20), as one revolved solid with a hex socket. The thread is a plain cylinder at the nominal major diameter over the thread length b; no real thread, thread neck, head chamfer or underhead radius, because the tables do not give them. Shoulder length is yours to choose; edit the model for another l1.
- Inch shoulder screws (ASME B18.3) are on the companion page. McMaster-Carr's shoulder screw category with an ISO 7379 filter is linked below (free per-part STEP/IGES there; not hosted here).

## Sizes

| thread d2 | pitch P, mm | shoulder Ø d1, mm (other sources) | head Ø d3 (max), mm | head height k, mm (fasten.it k max) | hex key s, mm | thread length b (max), mm | socket depth t (min), mm | shoulder length l1 range, mm (fasten.it / Ganter) |
|---|---|---|---|---|---|---|---|---|
| M5 | 0.8 | 6 (fasten.it 6.5) | 10 | 5 (4.5) | 3 | 9.75 | 2.4 | 10–40 / 10–80 |
| M6 | 1 | 8 | 13 | 6 (5.5) | 4 | 11.25 | 3.3 | 12–50 / 16–100 |
| M8 | 1.25 | 10 | 16 | 8 (7) | 5 | 13.25 | 4.2 | 16–120 / 16–100 |
| M10 | 1.5 | 13 (Ganter 12) | 18 | 10 (9) | 6 | 16.4 | 4.9 | 16–120 / 16–100 |
| M12 | 1.75 | 16 | 24 | 12 (11) | 8 | 18.4 | 6.6 | 30–120 / 25–100 |
| M16 | 2 | 20 | 30 | 16 (14) | 10 | 22.4 | 8.8 | 40–120 / 30–100 |
| M20 | 2.5 | 25 (Ganter 24) | 36 | 20 (16) | 12 | 27.4 | 10 | 50–120 / 50–100 |

## Where the files are

- iTeh Standards: [ISO 7379:1983 sample pages: shoulder d1, thread, head d, k, socket s, preferred lengths](https://cdn.standards.iteh.ai/samples/14078/66d6be2c979341abb895fa52330708be/ISO-7379-1983.pdf) — web — Publisher's page; dimensions are facts
- fasten.it: [ISO 7379 Standard dimensions for hexagon socket head shoulder screws (M5 to M20): thread length b max, socket depth t min, k max](https://fasten.it/en/norms/norm/iso_7379) — web — Publisher's page; dimensions are facts
- Ganter Norm: [ISO 7379 shoulder screws, steel, with collar: d1, d2, l1, d3, s (and the 4 / M3, 5 / M4 non-ISO sizes)](https://ganternorm.com/en/products/3.2-Mounting-positioning-levelling-with-screws-clamping-and-supporting-elements/Swing-bolts-Shoulder-screws-Thrust-bolts/ISO-7379-Shoulder-screws) — web — Publisher's page; dimensions are facts
- SKDIN (distributor, McMaster part mirror): [M5 ISO 7379 shoulder screw 92981A149: 6 mm shoulder, head 10 x 5, socket 3](https://www.skdin.com/products/productid-0537FA00027) — web — Publisher's page; dimensions are facts
- SKDIN (distributor, McMaster part mirror): [M10 ISO 7379 shoulder screw 90265A374: 13 mm shoulder, head 19 x 10](https://www.skdin.com/products/productid-0543FA00205) — web — Publisher's page; dimensions are facts
- Accu Components: [M10 x 20 socket shoulder screw ISO 7379 (12 mm shoulder, 16.4 thread length, head 18 x 8.9)](https://accu-components.com/us/metric-socket-shoulder-screws/10490-SSH-M10-20-12-9) — web — Publisher's page; dimensions are facts
- McMaster-Carr: [Shoulder screws, ISO 7379 filter (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/shoulder-screws/specifications-met~iso-7379) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)
- McMaster-Carr: [Steel shoulder screws (inch and metric) (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/steel-shoulder-screws/) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Free STEP/STL (7 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/index.json

- shoulder-screw-iso-7379-m5-shoulder-6x40: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m5-shoulder-6x40.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m5-shoulder-6x40.stl) — ISO 7379 shoulder screw M5: shoulder Ø6 × 40 mm long, thread M5 × 9.75 mm (drawn as a plain Ø5 cylinder, nominal major diameter), head Ø10 × 5, 3 mm hex socket 2.4 mm deep; the 40 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck
- shoulder-screw-iso-7379-m6-shoulder-8x40: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m6-shoulder-8x40.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m6-shoulder-8x40.stl) — ISO 7379 shoulder screw M6: shoulder Ø8 × 40 mm long, thread M6 × 11.25 mm (drawn as a plain Ø6 cylinder, nominal major diameter), head Ø13 × 6, 4 mm hex socket 3.3 mm deep; the 40 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck
- shoulder-screw-iso-7379-m8-shoulder-10x40: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m8-shoulder-10x40.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m8-shoulder-10x40.stl) — ISO 7379 shoulder screw M8: shoulder Ø10 × 40 mm long, thread M8 × 13.25 mm (drawn as a plain Ø8 cylinder, nominal major diameter), head Ø16 × 8, 5 mm hex socket 4.2 mm deep; the 40 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck
- shoulder-screw-iso-7379-m10-shoulder-13x40: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m10-shoulder-13x40.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m10-shoulder-13x40.stl) — ISO 7379 shoulder screw M10: shoulder Ø13 × 40 mm long, thread M10 × 16.4 mm (drawn as a plain Ø10 cylinder, nominal major diameter), head Ø18 × 10, 6 mm hex socket 4.9 mm deep; the 40 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck
- shoulder-screw-iso-7379-m12-shoulder-16x40: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m12-shoulder-16x40.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m12-shoulder-16x40.stl) — ISO 7379 shoulder screw M12: shoulder Ø16 × 40 mm long, thread M12 × 18.4 mm (drawn as a plain Ø12 cylinder, nominal major diameter), head Ø24 × 12, 8 mm hex socket 6.6 mm deep; the 40 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck
- shoulder-screw-iso-7379-m16-shoulder-20x40: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m16-shoulder-20x40.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m16-shoulder-20x40.stl) — ISO 7379 shoulder screw M16: shoulder Ø20 × 40 mm long, thread M16 × 22.4 mm (drawn as a plain Ø16 cylinder, nominal major diameter), head Ø30 × 16, 10 mm hex socket 8.8 mm deep; the 40 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck
- shoulder-screw-iso-7379-m20-shoulder-25x50: [STEP](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m20-shoulder-25x50.step) · [STL](https://xemstudio.com/files/hardware/shoulder-screws-iso-7379/shoulder-screw-iso-7379-m20-shoulder-25x50.stl) — ISO 7379 shoulder screw M20: shoulder Ø25 × 50 mm long, thread M20 × 27.4 mm (drawn as a plain Ø20 cylinder, nominal major diameter), head Ø36 × 20, 12 mm hex socket 10 mm deep; the 50 mm shoulder length is an example from the standard's range, head height k and socket depth t are the larger/single-source values noted on the page; no chamfers or thread neck

## Questions

**What size is an M8 ISO 7379 shoulder screw?**

10 mm shoulder, M8 × 1.25 thread 13.25 mm long (max), head Ø16 × 8, 5 mm hex key.

**What hex key fits an M6 shoulder bolt?**

4 mm: the M6 (8 mm shoulder) ISO 7379 screw has a 4 mm hex socket and a Ø13 head.

**Do all sources agree on the shoulder diameter?**

Not for M5 (6 vs 6.5), M10 (13 vs 12) and M20 (25 vs 24); the page shows both and the files use 6, 13 and 25.

## Fits with

- [Shoulder screws ASME B18.3 (inch): shoulder Ø 1/4 to 3/4 in, thread, head size, hex key, thread length](https://xemstudio.com/objects/shoulder-screws-asme-b18-3/)
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)
- [Socket head cap screws, M10 to M24 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric-m10-m24/)
- [Clevis pins ISO 2341 B, Ø3 to Ø8](https://xemstudio.com/objects/clevis-pins/)
- [Dowel pins, 2–6 mm (ISO 2338 / DIN 6325)](https://xemstudio.com/objects/dowel-pins-metric/)
- [Ball bearings, 683 to 6210 and flanged F6xx (ISO 15)](https://xemstudio.com/objects/ball-bearings-metric/)