# Button head socket screws, M2–M8 (ISO 7380)

> How big is an M3 button head screw head?

- Category: Hardware › Fasteners
- Kind: Hardware
- Basis: ISO 7380-1
- Page: https://xemstudio.com/objects/button-head-screws-metric/ · JSON: https://xemstudio.com/api/geometry?object=button-head-screws-metric · Plain text: https://xemstudio.com/objects/button-head-screws-metric/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Notes

- Low domed head for appearance; no counterbore needed. Head diameter ≈ 1.9 × thread, head height ≈ 0.55 × thread.
- Smaller hex than a cap screw of the same thread (M3 uses 2 mm, M6 uses 4 mm), so torque lower; fine for plastic parts.

## Sizes

| thread | head_dia_mm | head_height_mm | hex_key_mm |
|---|---|---|---|
| M2 | 3.5 | 1.3 | 1.3 |
| M2.5 | 4.7 | 1.5 | 1.5 |
| M3 | 5.7 | 1.65 | 2.0 |
| M4 | 7.6 | 2.2 | 2.5 |
| M5 | 9.5 | 2.75 | 3.0 |
| M6 | 10.5 | 3.3 | 4.0 |
| M8 | 14.0 | 4.4 | 5.0 |

## Where the files are

- McMaster-Carr: [Socket head screws (free STEP/IGES/STL per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/socket-head-screws/) — STEP, IGES, STL, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)
- Wikipedia: [Screw](https://en.wikipedia.org/wiki/Screw) — web — CC BY-SA 4.0 (text)

## Free STEP/STL (35 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/button-head-screws-metric/index.json

- button-m2x4: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x4.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x4.stl) — ISO 7380 M2 × 4, thread as plain cylinder
- button-m2x6: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x6.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x6.stl) — ISO 7380 M2 × 6, thread as plain cylinder
- button-m2x8: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x8.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x8.stl) — ISO 7380 M2 × 8, thread as plain cylinder
- button-m2x10: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x10.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2x10.stl) — ISO 7380 M2 × 10, thread as plain cylinder
- button-m2.5x6: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x6.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x6.stl) — ISO 7380 M2.5 × 6, thread as plain cylinder
- button-m2.5x8: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x8.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x8.stl) — ISO 7380 M2.5 × 8, thread as plain cylinder
- button-m2.5x10: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x10.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x10.stl) — ISO 7380 M2.5 × 10, thread as plain cylinder
- button-m2.5x12: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x12.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m2.5x12.stl) — ISO 7380 M2.5 × 12, thread as plain cylinder
- button-m3x6: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x6.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x6.stl) — ISO 7380 M3 × 6, thread as plain cylinder
- button-m3x8: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x8.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x8.stl) — ISO 7380 M3 × 8, thread as plain cylinder
- button-m3x10: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x10.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x10.stl) — ISO 7380 M3 × 10, thread as plain cylinder
- button-m3x12: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x12.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x12.stl) — ISO 7380 M3 × 12, thread as plain cylinder
- button-m3x16: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x16.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x16.stl) — ISO 7380 M3 × 16, thread as plain cylinder
- button-m3x20: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x20.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m3x20.stl) — ISO 7380 M3 × 20, thread as plain cylinder
- button-m4x8: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x8.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x8.stl) — ISO 7380 M4 × 8, thread as plain cylinder
- button-m4x10: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x10.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x10.stl) — ISO 7380 M4 × 10, thread as plain cylinder
- button-m4x12: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x12.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x12.stl) — ISO 7380 M4 × 12, thread as plain cylinder
- button-m4x16: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x16.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x16.stl) — ISO 7380 M4 × 16, thread as plain cylinder
- button-m4x20: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x20.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x20.stl) — ISO 7380 M4 × 20, thread as plain cylinder
- button-m4x25: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x25.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m4x25.stl) — ISO 7380 M4 × 25, thread as plain cylinder
- button-m5x10: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x10.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x10.stl) — ISO 7380 M5 × 10, thread as plain cylinder
- button-m5x12: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x12.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x12.stl) — ISO 7380 M5 × 12, thread as plain cylinder
- button-m5x16: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x16.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x16.stl) — ISO 7380 M5 × 16, thread as plain cylinder
- button-m5x20: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x20.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x20.stl) — ISO 7380 M5 × 20, thread as plain cylinder
- button-m5x25: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x25.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m5x25.stl) — ISO 7380 M5 × 25, thread as plain cylinder
- button-m6x12: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x12.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x12.stl) — ISO 7380 M6 × 12, thread as plain cylinder
- button-m6x16: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x16.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x16.stl) — ISO 7380 M6 × 16, thread as plain cylinder
- button-m6x20: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x20.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x20.stl) — ISO 7380 M6 × 20, thread as plain cylinder
- button-m6x25: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x25.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x25.stl) — ISO 7380 M6 × 25, thread as plain cylinder
- button-m6x30: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x30.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m6x30.stl) — ISO 7380 M6 × 30, thread as plain cylinder
- button-m8x16: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x16.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x16.stl) — ISO 7380 M8 × 16, thread as plain cylinder
- button-m8x20: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x20.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x20.stl) — ISO 7380 M8 × 20, thread as plain cylinder
- button-m8x25: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x25.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x25.stl) — ISO 7380 M8 × 25, thread as plain cylinder
- button-m8x30: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x30.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x30.stl) — ISO 7380 M8 × 30, thread as plain cylinder
- button-m8x40: [STEP](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x40.step) · [STL](https://xemstudio.com/files/hardware/button-head-screws-metric/button-m8x40.stl) — ISO 7380 M8 × 40, thread as plain cylinder

## Questions

**What size is an M3 button head screw head?**

5.7 mm diameter, 1.65 mm tall, 2 mm hex key (ISO 7380). Clearance hole 3.4 mm, or 3.6 in a print.

**What size is an M5 button head screw head?**

9.5 mm diameter, 2.75 mm tall, 3 mm hex key. 2020 extrusion T-nut screws are usually M5 button heads 8–10 mm long.

## Fits with

- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)
- [Countersunk socket screws, M2–M8 (ISO 10642 / DIN 7991)](https://xemstudio.com/objects/countersunk-screws-metric/)
- [2020 aluminum extrusion](https://xemstudio.com/objects/2020-extrusion/)
- [Flat washers, M2–M8 (ISO 7089)](https://xemstudio.com/objects/flat-washers-metric/)