# Hexalobular (Torx) socket screws: ISO 14579 cap, ISO 14580 low cheese and ISO 14583 pan head, M2–M20: head diameter, height, socket number, depth + head envelopes

> What are the head diameter, head height and Torx size of an ISO 14579, 14580 or 14583 hexalobular socket screw (M3, M4, M5, M6, M8)?

- Category: Hardware › Fasteners
- Kind: Standard part
- Basis: fasten.it tables for ISO 14579, 14580 and 14583 cross-checked against Aspen Fasteners (ISO 14579) and Westfield Fasteners (ISO 14580 and 14583), which agree with fasten.it on every value read; 15 head-envelope models as files
- Page: https://xemstudio.com/objects/hexalobular-socket-screws-iso-14579-14580-14583/ · JSON: https://xemstudio.com/api/geometry?object=hexalobular-socket-screws-iso-14579-14580-14583 · Plain text: https://xemstudio.com/objects/hexalobular-socket-screws-iso-14579-14580-14583/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
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## Overall (mm)

| length | width | height |
|---|---|---|
| 16.0 | 16.0 | 36.0 |

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

## Notes

- Millimetres. ISO 14579 is the hexalobular socket head cap screw (like ISO 4762 with a hexalobular socket), M2 to M20, product grade A, with a plain and a knurled head diameter; ISO 14580 is the hexalobular socket cheese head screw with reduced head, M2 to M10; ISO 14583 is the hexalobular socket pan head screw, M2 to M10. Columns: dk head diameter and k head height (nominal = max, with min where Westfield prints it), socket number (the ISO 10664 hexalobular size, T-number), A and t (socket depth min / max). 'A ref' is the across-lobes figure of the socket; for socket 45 the screw tables print 7.95 mm and the ISO 10664:2014 sample prints 7.93 mm (see torx-hexalobular-drive-sizes-iso-10664).
- The last column carries the other numbers each source prints, with the source's own letters: for ISO 14579 b (a 16–52 value rising with size; the page does not define it) and w min (fasten.it); for ISO 14580 and 14583 a max, b min, da max, r min, w min (14580), rf (14583, equal to fasten.it's 'r ≈') and x max (Westfield). Neither source defines these letters in words. Units are not printed on Westfield's sheets; the values match fasten.it's mm tables.
- Aspen's ISO 14579 sheet uses its own labels (D, P, B, D1, K, drive size, A) and prints the same numbers as fasten.it for b, dk, k and A for every size M2 to M20. fasten.it's ISO 14580 and 14583 tables also match Westfield's for dk, k, socket number, A and t for every size M2 to M10 with one exception: ISO 14580 M6 t max is 2.29 on fasten.it and 2.26 on Westfield (this page shows 2.26 with the difference noted in the row; fasten.it prints t min / max in a different column order for 14583).
- Files are Xem-drawn head envelopes, not the real screw: a plain cylinder of diameter dk max and height k max on a plain shank at the nominal diameter (the thread is smaller at the root), M3 × 12, M4 × 16, M5 × 20, M6 × 25 and M8 × 30 mm under the head for each of the three standards. No hexalobular socket (its contour is not published as numbers in the pages read), no chamfer, no dome on the pan head (rf and r are listed only as references), no thread, no point. The example lengths are Xem's choices (they are in the length list fasten.it prints for ISO 14579; lengths for 14580 and 14583 were not read).
- Not on this page: countersunk (ISO 14581, 14584) and tapping (ISO 14585) hexalobular screws, which exist but were not tabulated. Hex socket versions: socket-head-cap-screws-metric; pan and cheese head Phillips: machine-screws-metric-pan-cheese-csk.

## Sizes

| standard | thread | pitch | dk max | dk min | k max | k min | socket no. (T size) | A | t min | t max | other numbers as printed (source's letters) |
|---|---|---|---|---|---|---|---|---|---|---|---|
| ISO 14579 cap | M2 | 0.4 | 3.8 | — | 2 | — | 6 | 1.75 | 0.71 | 0.84 | b 16; w min 0.55; knurled dk max 3.98 |
| ISO 14579 cap | M2.5 | 0.45 | 4.5 | — | 2.5 | — | 8 | 2.4 | 0.91 | 1.04 | b 17; w min 0.85; knurled dk max 4.68 |
| ISO 14579 cap | M3 | 0.5 | 5.5 | — | 3 | — | 10 | 2.8 | 1.01 | 1.27 | b 18; w min 1.15; knurled dk max 5.68 |
| ISO 14579 cap | M4 | 0.7 | 7 | — | 4 | — | 20 | 3.95 | 1.42 | 1.8 | b 20; w min 1.4; knurled dk max 7.22 |
| ISO 14579 cap | M5 | 0.8 | 8.5 | — | 5 | — | 25 | 4.5 | 1.65 | 2.03 | b 22; w min 1.9; knurled dk max 8.72 |
| ISO 14579 cap | M6 | 1 | 10 | — | 6 | — | 30 | 5.6 | 2.02 | 2.42 | b 24; w min 2.3; knurled dk max 10.22 |
| ISO 14579 cap | M8 | 1.25 | 13 | — | 8 | — | 45 | 7.95 | 2.92 | 3.31 | b 28; w min 3.3; knurled dk max 13.27 |
| ISO 14579 cap | M10 | 1.5 | 16 | — | 10 | — | 50 | 8.95 | 3.62 | 4.02 | b 32; w min 4; knurled dk max 16.27 |
| ISO 14579 cap | M12 | 1.75 | 18 | — | 12 | — | 55 | 11.35 | 4.82 | 5.21 | b 36; w min 4.8; knurled dk max 18.27 |
| ISO 14579 cap | M14 | 2 | 21 | — | 14 | — | 60 | 13.45 | 5.62 | 5.99 | b 40; w min 5.8; knurled dk max 21.33 |
| ISO 14579 cap | M16 | 2 | 24 | — | 16 | — | 70 | 15.7 | 6.62 | 7.01 | b 44; w min 6.8; knurled dk max 24.33 |
| ISO 14579 cap | M18 | 2.5 | 27 | — | 18 | — | 80 | 17.75 | 7.5 | 8 | b 48; w min 7.8; knurled dk max 27.33 |
| ISO 14579 cap | M20 | 2.5 | 30 | — | 20 | — | 90 | 20.2 | 8.69 | 9.2 | b 52; w min 8.6; knurled dk max 30.33 |
| ISO 14580 low cheese | M2 | 0.4 | 3.8 | 3.62 | 1.55 | 1.41 | 6 | 1.75 | 0.71 | 0.84 | a max 0.8; b min 25; da max 2.6; r min 0.1; w min 0.5; x max 1.0 |
| ISO 14580 low cheese | M2.5 | 0.45 | 4.5 | 4.32 | 1.85 | 1.71 | 8 | 2.4 | 0.78 | 0.91 | a max 0.9; b min 25; da max 3.1; r min 0.1; w min 0.7; x max 1.1 |
| ISO 14580 low cheese | M3 | 0.5 | 5.5 | 5.32 | 2.4 | 2.26 | 10 | 2.8 | 1.01 | 1.27 | a max 1; b min 25; da max 3.6; r min 0.1; w min 0.75; x max 1.25 |
| ISO 14580 low cheese | M3.5 | 0.6 | 6 | 5.82 | 2.6 | 2.46 | 15 | 3.35 | 1.07 | 1.33 | a max 1.2; b min 38; da max 4.1; r min 0.1; w min 1.0; x max 1.5 |
| ISO 14580 low cheese | M4 | 0.7 | 7 | 6.78 | 3.1 | 2.92 | 20 | 3.95 | 1.27 | 1.66 | a max 1.4; b min 38; da max 4.7; r min 0.2; w min 1.1; x max 1.75 |
| ISO 14580 low cheese | M5 | 0.8 | 8.5 | 8.28 | 3.65 | 3.47 | 25 | 4.5 | 1.52 | 1.91 | a max 1.6; b min 38; da max 5.7; r min 0.2; w min 1.3; x max 2.0 |
| ISO 14580 low cheese | M6 | 1 | 10 | 9.78 | 4.4 | 4.1 | 30 | 5.6 | 1.9 | 2.26 | a max 2; b min 38; da max 6.8; r min 0.25; w min 1.6; x max 2.5; fasten.it prints t max 2.29 for M6 against Westfield's 2.26 (Westfield's value shown) |
| ISO 14580 low cheese | M8 | 1.25 | 13 | 12.73 | 5.8 | 5.5 | 45 | 7.95 | 2.66 | 3.05 | a max 2.5; b min 38; da max 9.2; r min 0.4; w min 2.0; x max 3.2 |
| ISO 14580 low cheese | M10 | 1.5 | 16 | 15.73 | 6.9 | 6.54 | 50 | 8.95 | 3.04 | 3.43 | a max 3; b min 38; da max 11.2; r min 0.4; w min 2.4; x max 3.8 |
| ISO 14583 pan | M2 | 0.4 | 4 | 3.7 | 1.6 | 1.46 | 6 | 1.75 | 0.63 | 0.77 | a max 0.8; b min 25; da max 2.6; r min 0.1; rf 3.2; x max 1.0 |
| ISO 14583 pan | M2.5 | 0.45 | 5 | 4.7 | 2.1 | 1.96 | 8 | 2.4 | 0.91 | 1.04 | a max 0.9; b min 25; da max 3.1; r min 0.1; rf 4; x max 1.1 |
| ISO 14583 pan | M3 | 0.5 | 5.6 | 5.3 | 2.4 | 2.26 | 10 | 2.8 | 1.01 | 1.27 | a max 1; b min 25; da max 3.6; r min 0.1; rf 5; x max 1.25 |
| ISO 14583 pan | M3.5 | 0.6 | 7 | 6.64 | 2.6 | 2.46 | 15 | 3.35 | 1.07 | 1.33 | a max 1.2; b min 38; da max 4.1; r min 0.1; rf 6; x max 1.5 |
| ISO 14583 pan | M4 | 0.7 | 8 | 7.64 | 3.1 | 2.92 | 20 | 3.95 | 1.27 | 1.66 | a max 1.4; b min 38; da max 4.7; r min 0.2; rf 6.5; x max 1.75 |
| ISO 14583 pan | M5 | 0.8 | 9.5 | 9.14 | 3.7 | 3.52 | 25 | 4.5 | 1.52 | 1.91 | a max 1.6; b min 38; da max 5.7; r min 0.2; rf 8; x max 2.0 |
| ISO 14583 pan | M6 | 1 | 12 | 11.57 | 4.6 | 4.3 | 30 | 5.6 | 2.02 | 2.42 | a max 2; b min 38; da max 6.8; r min 0.25; rf 10; x max 2.5 |
| ISO 14583 pan | M8 | 1.25 | 16 | 15.57 | 6 | 5.7 | 45 | 7.95 | 2.79 | 3.18 | a max 2.5; b min 38; da max 9.2; r min 0.4; rf 13; x max 3.2 |
| ISO 14583 pan | M10 | 1.5 | 20 | 19.48 | 7.5 | 7.14 | 50 | 8.95 | 3.62 | 4.02 | a max 3; b min 38; da max 11.2; r min 0.4; rf 16; x max 3.8 |

## Where the files are

- fasten.it: [DIN EN ISO 14579 hexalobular socket head cap screws M2 to M20 (grade A): b, dk (plain and knurled), k, w, socket no., A, t; lengths per size, 06/2011](https://www.fasten.it/norms/norm/din_en_iso_14579) — web — Reference page; numbers only. Pitch, b and A are not marked max or min
- Aspen Fasteners: [Metric ISO 14579 spec: D, P, B, D1, K, 6-lobe drive size, A for M2 to M20 (labels as printed; agrees with fasten.it)](https://www.aspenfasteners.com/content/pdf/Metric_ISO_14579_spec.pdf) — web — Maker spec sheet; numbers only
- fasten.it: [DIN EN ISO 14580 hexalobular socket cheese head screws with reduced head M2 to M10: P, dk, k, w, socket no., A, t, 2011](https://fasten.it/en/norms/norm/din_en_iso_14580) — web — Reference page; numbers only. dk and k are nominal = max
- Westfield Fasteners: [ScrewBolt TXCapLow14580: ISO 14580 d, p, a, b, dk (max, min), da, k (max, min), r, w, x, socket no., A, t (max, min), M2 to M10](https://westfieldfasteners.co.uk/Standards/ScrewBolt-TXCapLow14580-M.pdf) — web — Maker / stockist standards sheet; numbers only. Units are not stated, mm by the neighbouring shank-length table
- fasten.it: [DIN EN ISO 14583 hexalobular socket pan head screws M2 to M10 (grade A): P, dk, k, r, socket no., A, t, 2011](https://www.fasten.it/norms/norm/din_en_iso_14583) — web — Reference page; numbers only. dk and k are nominal = max
- Westfield Fasteners: [ScrewBolt TXPan14583: ISO 14583 d, p, a, b, da, dk (max, min), k (max, min), r, rf, x, socket no., A, t (max, min), M2 to M10](https://westfieldfasteners.co.uk/Standards/ScrewBolt-TXPan14583-M.pdf) — web — Maker / stockist standards sheet; numbers only
- McMaster-Carr: [Tamper-resistant (pin-in) Torx bits, T7 to T55 (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/torx-security-bits) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Free STEP/STL (15 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/index.json

- iso-14579-m3x12-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m3x12-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m3x12-head-envelope.stl) — ISO 14579 M3 head envelope: plain cylinder Ø5.5 × 3 mm (dk max × k max) on a plain Ø3 shank, example length 12 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14579-m4x16-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m4x16-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m4x16-head-envelope.stl) — ISO 14579 M4 head envelope: plain cylinder Ø7 × 4 mm (dk max × k max) on a plain Ø4 shank, example length 16 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14579-m5x20-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m5x20-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m5x20-head-envelope.stl) — ISO 14579 M5 head envelope: plain cylinder Ø8.5 × 5 mm (dk max × k max) on a plain Ø5 shank, example length 20 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14579-m6x25-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m6x25-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m6x25-head-envelope.stl) — ISO 14579 M6 head envelope: plain cylinder Ø10 × 6 mm (dk max × k max) on a plain Ø6 shank, example length 25 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14579-m8x30-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m8x30-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14579-m8x30-head-envelope.stl) — ISO 14579 M8 head envelope: plain cylinder Ø13 × 8 mm (dk max × k max) on a plain Ø8 shank, example length 30 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14580-m3x12-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m3x12-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m3x12-head-envelope.stl) — ISO 14580 M3 head envelope: plain cylinder Ø5.5 × 2.4 mm (dk max × k max) on a plain Ø3 shank, example length 12 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14580-m4x16-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m4x16-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m4x16-head-envelope.stl) — ISO 14580 M4 head envelope: plain cylinder Ø7 × 3.1 mm (dk max × k max) on a plain Ø4 shank, example length 16 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14580-m5x20-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m5x20-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m5x20-head-envelope.stl) — ISO 14580 M5 head envelope: plain cylinder Ø8.5 × 3.65 mm (dk max × k max) on a plain Ø5 shank, example length 20 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14580-m6x25-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m6x25-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m6x25-head-envelope.stl) — ISO 14580 M6 head envelope: plain cylinder Ø10 × 4.4 mm (dk max × k max) on a plain Ø6 shank, example length 25 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14580-m8x30-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m8x30-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14580-m8x30-head-envelope.stl) — ISO 14580 M8 head envelope: plain cylinder Ø13 × 5.8 mm (dk max × k max) on a plain Ø8 shank, example length 30 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14583-m3x12-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m3x12-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m3x12-head-envelope.stl) — ISO 14583 M3 head envelope: plain cylinder Ø5.6 × 2.4 mm (dk max × k max) on a plain Ø3 shank, example length 12 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14583-m4x16-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m4x16-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m4x16-head-envelope.stl) — ISO 14583 M4 head envelope: plain cylinder Ø8 × 3.1 mm (dk max × k max) on a plain Ø4 shank, example length 16 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14583-m5x20-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m5x20-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m5x20-head-envelope.stl) — ISO 14583 M5 head envelope: plain cylinder Ø9.5 × 3.7 mm (dk max × k max) on a plain Ø5 shank, example length 20 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14583-m6x25-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m6x25-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m6x25-head-envelope.stl) — ISO 14583 M6 head envelope: plain cylinder Ø12 × 4.6 mm (dk max × k max) on a plain Ø6 shank, example length 25 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread
- iso-14583-m8x30-head-envelope: [STEP](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m8x30-head-envelope.step) · [STL](https://xemstudio.com/files/hardware/hexalobular-socket-screws-iso-14579-14580-14583/iso-14583-m8x30-head-envelope.stl) — ISO 14583 M8 head envelope: plain cylinder Ø16 × 6 mm (dk max × k max) on a plain Ø8 shank, example length 30 mm under the head (Xem's choice); no hexalobular socket, chamfer, dome or thread

## Questions

**What is the head diameter of an M5 ISO 14579 Torx cap screw?**

8.5 mm max and 5 mm high, with socket number 25 (T25), A 4.5 mm and socket depth 1.65 to 2.03 mm (fasten.it and Aspen).

**What Torx size does an M4 pan head ISO 14583 screw use?**

Socket 20 (T20), A 3.95 mm; head dk 8 mm max (7.64 min), height 3.1 mm max (2.92 min); socket depth 1.27 to 1.66 mm (Westfield; fasten.it agrees).

**Is an ISO 14580 head lower than an ISO 14579 head?**

Yes. For M6, ISO 14580 is 10 mm across and 4.4 mm high; ISO 14579 is 10 mm across and 6 mm high.

## Fits with

- [Torx / hexalobular drive sizes T1–T100 (ISO 10664): A and B across lobes, gauge limits for A, B, Ri, Re and depth H, and the screw size each fits](https://xemstudio.com/objects/torx-hexalobular-drive-sizes-iso-10664/)
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)
- [Metric machine screws M1.6–M10: pan head ISO 7045 (cross) / ISO 1580 (slotted), cheese head ISO 1207, countersunk ISO 7046-1 — head sizes, recess sizes + models](https://xemstudio.com/objects/machine-screws-metric-pan-cheese-csk/)
- [Countersunk socket screws, M2–M8 (ISO 10642 / DIN 7991)](https://xemstudio.com/objects/countersunk-screws-metric/)
- [Button head socket screws, M2–M8 (ISO 7380)](https://xemstudio.com/objects/button-head-screws-metric/)
- [Self-tapping (sheet metal) screws: ISO 7049 pan head ST2.2–ST6.3 and ASME B18.6.4 Type AB thread #2 to 3/8](https://xemstudio.com/objects/self-tapping-screws-iso-7049-pan-head/)