# LM8UU linear bearing and 8 mm rod

> What are the LM8UU bearing dimensions and the housing bore?

- Category: Hardware › Motion
- Kind: Hardware
- Basis: industry standard (ISO 10285 style)
- Page: https://xemstudio.com/objects/lm8uu-linear-bearing/ · JSON: https://xemstudio.com/api/geometry?object=lm8uu-linear-bearing · Plain text: https://xemstudio.com/objects/lm8uu-linear-bearing/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); linked files under their publishers' licenses

## Overall (mm)

| length | width | height |
|---|---|---|
| 24 | 15 | 15 |

## Notes

- Bore 8 mm, OD 15 mm, length 24 mm; two retaining-ring grooves. LM8LUU is 45 mm long. LM10UU is 10 × 19 × 29, LM12UU 12 × 21 × 30.
- Printed housing: Ø15.2–15.3 mm; clamp-style housings hold better than a straight press.

## Where the files are

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

## Free STEP/STL (2 parts, CC BY 4.0, Xem Studio)

Index: https://xemstudio.com/files/hardware/lm8uu-linear-bearing/index.json

- lm8uu: [STEP](https://xemstudio.com/files/hardware/lm8uu-linear-bearing/lm8uu.step) · [STL](https://xemstudio.com/files/hardware/lm8uu-linear-bearing/lm8uu.stl) — LM8UU envelope with ring grooves
- rod-8x300: [STEP](https://xemstudio.com/files/hardware/lm8uu-linear-bearing/rod-8x300.step) · [STL](https://xemstudio.com/files/hardware/lm8uu-linear-bearing/rod-8x300.stl) — 8 mm rod, 300 mm

## Questions

**What are LM8UU bearing dimensions?**

8 mm bore, 15 mm OD, 24 mm long, two retaining-ring grooves. LM8LUU is the 45 mm long version.

**What hole size for an LM8UU in a 3D printed housing?**

15.2–15.3 mm; a clamp-style housing with a slot and screw holds better than a straight press fit.

## Fits with

- [NEMA 17 stepper motor](https://xemstudio.com/objects/nema-17-stepper/)
- [2020 aluminum extrusion](https://xemstudio.com/objects/2020-extrusion/)
- [Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)](https://xemstudio.com/objects/socket-head-cap-screws-metric/)