THK LM5UU Linear Ball Bushing
The LM5UU is a compact, closed‑type linear ball bushing from THK's standard LM‑UU series. It features a resin retainer, UU double‑lip dust seals, and a 4‑row ball recirculation design, delivering smooth, low‑friction linear motion with stable radial load support. Ideal for precision instruments, small automation equipment, and compact linear guidance systems.
The LM5UU is a compact, closed‑type linear ball bushing from THK’s standard LM‑UU series. It features a resin retainer, UU double‑lip dust seals, and a 4‑row ball recirculation design, delivering smooth, low‑friction linear motion with stable radial load support. Ideal for precision instruments, small automation equipment, and compact linear guidance systems.
Official Specifications
| Parameter | Value | Unit |
|---|---|---|
| Inner bore diameter (dr) | 5 | mm |
| Outer diameter (D) | 10 | mm |
| Overall length (L) | 15 | mm |
| Distance between retaining rings (B) | 10.2 | mm |
| Retaining ring width (W) | 1.1 | mm |
| Retaining ring diameter (D1) | 9.6 | mm |
| Number of ball rows | 4 | — |
| Basic dynamic load rating (C) | 167 | N |
| Basic static load rating (C₀) | 206 | N |
| Mass | 11 | g |
| Bore diameter tolerance (High grade) | 0 / –0.008 | mm |
| Outer diameter tolerance (High grade) | 0 / –0.012 | mm |
| Length tolerance | ±0.20 | mm |
| Max eccentricity | 8 | μm |
| Radial clearance (High grade) | –3 | μm |
| Retainer material | Resin | — |
| Outer sleeve material | High‑carbon chromium bearing steel (SUJ2) | — |
| Ball material | Hardened steel | — |
| Operating temperature range | –10°C to +80°C | °C |
| Seal type | UU (double‑lip seals) | — |
| Lubrication | Pre‑lubricated with rust‑preventive oil; lithium‑based grease recommended | — |
Key Features
- Compact design: Miniature size (5×10×15 mm) for space‑constrained applications.
- UU double‑lip seals: Effective dust and moisture protection, extending service life.
- Resin retainer: Lightweight, low‑noise operation with stable ball guidance.
- High precision: Strict dimensional tolerances ensure smooth motion and interchangeability.
- Standard dimensions: Fully compatible with THK LM‑series shafts and metric linear motion systems.
Official Notes
- Designed exclusively for linear motion; not for pure rotational or moment loads. Use multiple bushings on a single shaft to resist moment loads.
- Recommended lubrication: THK AFB‑L grease or equivalent lithium‑based grease.
- Shaft requirements: Surface hardness ≥58 HRC, surface roughness Ra ≤0.4 μm.
- Operating temperature must not exceed 80°C to prevent resin retainer degradation.
