# T8 lead screw and brass nut (Tr8×8, 2 mm pitch 4-start)

> What are the T8 lead screw nut flange dimensions?

- Category: Hardware › Motion
- Kind: Hardware
- Basis: Tr8×8(P2) trapezoidal lead screw as sold for 3D printers; nut dimensions from common catalogues
- Page: https://xemstudio.com/objects/lead-screw-t8/ · JSON: https://xemstudio.com/api/geometry?object=lead-screw-t8 · Plain text: https://xemstudio.com/objects/lead-screw-t8/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Notes

- Ø8 mm screw, 2 mm pitch, 4 starts → 8 mm lead (one turn = 8 mm). Tr8×2 single-start (2 mm lead) exists and looks identical; check the spec.
- Brass nut: Ø10.2 body, 15 mm long, Ø22 flange 3.5 mm thick, four Ø3.5 holes on a 16 mm circle (M3). Print the pocket for the flange at Ø22.3.
- Couple to a NEMA 17 with a 5 → 8 mm coupler, or buy the screw with an integrated motor.

## Sizes

| part | dia_mm | length_mm | detail |
|---|---|---|---|
| screw | 8 | 100–400 | Tr8×8(P2), 4-start |
| nut body | 10.2 | 15 | brass, Tr8×8 |
| nut flange | 22 | 3.5 | 4 × Ø3.5 on 16 PCD |

## Where the files are

- Wikipedia: [Leadscrew](https://en.wikipedia.org/wiki/Leadscrew) — web — CC BY-SA 4.0 (text)
- McMaster-Carr: [Lead screws and nuts (free STEP/IGES/STL per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/lead-screws/) — STEP, IGES, STL, 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/lead-screw-t8/index.json

- t8-screw-100: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-100.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-100.stl) — T8 lead screw envelope Ø8 × 100 (thread not modeled)
- t8-screw-150: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-150.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-150.stl) — T8 lead screw envelope Ø8 × 150 (thread not modeled)
- t8-screw-200: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-200.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-200.stl) — T8 lead screw envelope Ø8 × 200 (thread not modeled)
- t8-screw-250: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-250.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-250.stl) — T8 lead screw envelope Ø8 × 250 (thread not modeled)
- t8-screw-300: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-300.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-300.stl) — T8 lead screw envelope Ø8 × 300 (thread not modeled)
- t8-screw-400: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-400.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-screw-400.stl) — T8 lead screw envelope Ø8 × 400 (thread not modeled)
- t8-brass-nut: [STEP](https://xemstudio.com/files/hardware/lead-screw-t8/t8-brass-nut.step) · [STL](https://xemstudio.com/files/hardware/lead-screw-t8/t8-brass-nut.stl) — T8 brass nut: Ø10.2 body, Ø22 flange 3.5 thick, 4 × Ø3.5 on 16 PCD, 15 long

## Questions

**What is the T8 nut hole pattern?**

Four Ø3.5 mm holes (M3) on a 16 mm pitch circle, at 45° to the axes; flange Ø22 × 3.5 mm.

**Is T8 lead 2 mm or 8 mm?**

Both are sold as 'T8'. Tr8×8 (4-start) moves 8 mm per turn; Tr8×2 moves 2 mm. Count the starts on the end of the screw: four visible thread ends = 8 mm lead.

## Fits with

- [NEMA 17 stepper motor](https://xemstudio.com/objects/nema-17-stepper/)
- [Flexible shaft couplers, 5–10 mm bores](https://xemstudio.com/objects/shaft-couplers/)
- [Ball bearings, 683 to 6210 and flanged F6xx (ISO 15)](https://xemstudio.com/objects/ball-bearings-metric/)
- [MGN9 / MGN12 / MGN15 miniature linear rails and carriages](https://xemstudio.com/objects/mgn-linear-rails/)
- [LM8UU linear bearing and 8 mm rod](https://xemstudio.com/objects/lm8uu-linear-bearing/)