# Linear ball bushings LM..UU and LM..LUU (LM8UU, LM10UU, LM12UU, LM16UU, LM20UU, long LUU): bore, OD, length, ring-groove numbers

> What are the dimensions of LM8UU, LM10UU, LM12UU, LM16UU, LM20UU and the long LM8LUU, LM10LUU, LM12LUU linear bearings: bore, OD, length and snap-ring groove?

- Category: Hardware › Bearings, rails & motion
- Kind: Standard part
- Basis: A Japanese-standard catalogue (DriveHQ) for d, D, L, B, W, D1, checked against WF International, Samick, Tuli, THK and McMaster; disagreements listed; McMaster-Carr linked for CAD
- Page: https://xemstudio.com/objects/linear-ball-bushings-lm-uu-luu/ · JSON: https://xemstudio.com/api/geometry?object=linear-ball-bushings-lm-uu-luu · Plain text: https://xemstudio.com/objects/linear-ball-bushings-lm-uu-luu/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files CC BY 4.0 or their publisher's license
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

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

## Notes

- The LM..UU linear ball bushing (linear bearing, ball bushing, 'LM8UU') is the cylindrical bushing on every 3D printer smooth rod and many CNC axes: the bore d is the shaft diameter, D the outside diameter, UU means a wiper seal at each end, L (long) doubles the ball set (LM8LUU is 45 long against 24). Two snap-ring grooves in the OD, groove width W and groove diameter D1, hold it in a housing with circlips.
- Numbers: the DriveHQ catalogue (maker not named, Japanese-standard dimensions) for d, D, L, B, W, D1. For LM8 to LM60, D and L equal the flanged LMF bodies on the flanged-bushing page (Samick, Tuli, THK, McMaster); for LM..LUU the DriveHQ table, WF International (L, W, D1) and a Misumi catalogue page (L, B, W, D1) agree on every row except L at 40 and 60 mm (see below), and Samick's LMF..L agrees on L. LM3UU and LM4UU come from CWL Bearing (d, D, L only).
- B is shown as printed and not defined in the sources' text (it is a dimension between the two grooves in the drawing). Misumi's own C-LMU series prints different B values (15.3 for the 8 mm bushing against 17.5 here), so B is catalogue-specific; because of that the grooves are not drawn in any file. The groove width W and groove diameter D1 are the same in every catalogue read where they could be matched (1.1 and 14.3 for LM8; 1.3 and 18 for LM10).
- Disagreements: LM40LUU is 154 (DriveHQ, WF International, Samick) against 151 (the Misumi catalogue page, Tuli LMK40LUU) and LM60LUU 211 against 209 (also McMaster's 60 mm flanged part). CWL Bearing prints LM6UU as 17 long and LM8SUU as 19; the DriveHQ, Samick and THK tables say LM6UU is 19 and LM8SUU is 17, so CWL's two rows are not used.
- Files: none on this page (a plain bushing with the grooves in unknown positions would be invented geometry). The flanged-bushing page has 20 solids built from the same d, D, L; for a plain press-in bushing use the bore d and OD D here. The existing LM8UU / 8 mm rod page has the 8 mm case.
- Left out: LM..UU above 60 mm, load ratings and tolerance grades (THK's housing bore tolerance table is H7 / J7 / H6 / J6 / K6 and its shaft table f6 / g6 / h6 / f5 / g5 / h5 / h7 / k6, mentioned in the mating table, not tabulated by size).

## Sizes

| designation | bore d (shaft Ø), mm | OD D, mm | length L, mm | B (as printed), mm | ring-groove width W, mm | ring-groove Ø D1, mm |
|---|---|---|---|---|---|---|
| LM3UU | 3 | 7 | 10 | — | — | — |
| LM4UU | 4 | 8 | 12 | — | — | — |
| LM5UU | 5 | 10 | 15 | 10.2 | 1.1 | 9.6 |
| LM6UU | 6 | 12 | 19 | 13.5 | 1.1 | 11.5 |
| LM8SUU | 8 | 15 | 17 | 11.5 | 1.1 | 14.3 |
| LM8UU | 8 | 15 | 24 | 17.5 | 1.1 | 14.3 |
| LM10UU | 10 | 19 | 29 | 22 | 1.3 | 18 |
| LM12UU | 12 | 21 | 30 | 23 | 1.3 | 20 |
| LM13UU | 13 | 23 | 32 | 23 | 1.3 | 22 |
| LM16UU | 16 | 28 | 37 | 26.5 | 1.6 | 27 |
| LM20UU | 20 | 32 | 42 | 30.5 | 1.6 | 30.5 |
| LM25UU | 25 | 40 | 59 | 41 | 1.85 | 38 |
| LM30UU | 30 | 45 | 64 | 44.5 | 1.85 | 43 |
| LM35UU | 35 | 52 | 70 | 49.5 | 2.1 | 49 |
| LM40UU | 40 | 60 | 80 | 60.5 | 2.1 | 57 |
| LM50UU | 50 | 80 | 100 | 74 | 2.6 | 76.5 |
| LM60UU | 60 | 90 | 110 | 85 | 3.15 | 86.5 |
| LM6LUU (long) | 6 | 12 | 35 | 27 | 1.1 | 11.5 |
| LM8LUU (long) | 8 | 15 | 45 | 35 | 1.1 | 14.3 |
| LM10LUU (long) | 10 | 19 | 55 | 44 | 1.3 | 18 |
| LM12LUU (long) | 12 | 21 | 57 | 46 | 1.3 | 20 |
| LM13LUU (long) | 13 | 23 | 61 | 46 | 1.3 | 22 |
| LM16LUU (long) | 16 | 28 | 70 | 53 | 1.6 | 27 |
| LM20LUU (long) | 20 | 32 | 80 | 61 | 1.6 | 30.5 |
| LM25LUU (long) | 25 | 40 | 112 | 82 | 1.85 | 38 |
| LM30LUU (long) | 30 | 45 | 123 | 89 | 1.85 | 43 |
| LM35LUU (long) | 35 | 52 | 135 | 99 | 2.1 | 49 |
| LM40LUU (long) | 40 | 60 | 154 | 121 | 2.1 | 57 |
| LM50LUU (long) | 50 | 80 | 192 | 148 | 2.6 | 76.5 |
| LM60LUU (long) | 60 | 90 | 211 | 170 | 3.15 | 86.5 |

## Where the files are

- Linear motion catalogue (maker not named; hosted on DriveHQ): [Ball bushes: LM..UU and LM..LUU (d, D, L, B, W, D1), LMF (d, D, L, D1, H, PCD, hole), LMK / LMH (K, W, A, F)](https://www.drivehq.com/file/df.aspx/isGallarytrue/shareID6477378/parentID26712025/fileID8191578157?1=1) — web — Publisher's page; dimensions are facts
- WF International: [LM..LUU long linear bearing: d, D, L, ring-groove numbers](https://www.wfint.com.tw/LM_L-Series/long-linear-bearing.html) — web — Publisher's page; dimensions are facts
- Misumi catalogue (India site, page 18): [LM..LUU long standard bushings: dr, D, L, B, W, D1 (L is 151 / 209 for LM40LUU / LM60LUU there)](https://in.c.misumi-ec.com/book/VONA1_MYT_V/pdf/0018.pdf) — web — Publisher's page; dimensions are facts
- CWL Bearing: [LM..UU linear motion bearings: d, D, L for LM3UU to LM60UU](https://cwlbearing.com/linear-motion-bearings) — web — Publisher's page; dimensions are facts
- Misumi: [C-LMU linear bushing (Misumi's own B, W, D1 differ from the LM..UU catalogues; used only to show the spread)](https://sg.misumi-ec.com/vona2/detail/110302580750/) — web — Publisher's page; dimensions are facts
- Samick (via AIMS Industrial): [Flanged linear bushing LMF, Asian standard catalogue p.70-71: d, D, L, D1, H, PCD, d1 x d2 x h](https://aimsindustrial.com.au/cdn/shop/files/Samick-Flanged-Linear-Bushing-LMF-Asian-Standard-Catalogue-Cover-and-Pages-70-71.pdf) — web — Publisher's page; dimensions are facts
- Samick (via AIMS Industrial): [Flanged long linear bushing LMF..L, Asian standard catalogue p.72-73: d, D, L, D1, H, PCD, d1 x d2 x h](https://aimsindustrial.com.au/cdn/shop/files/Samick-Flanged-Long-Linear-Bushing-LMF-L-Asian-Standard-Catalogue-Cover-and-Pages-72-73.pdf) — web — Publisher's page; dimensions are facts
- Tuli (distributor datasheet): [LMK..UU square flange linear bearings: d, D, L, flange square K, H, PCD, bolt hole d1 x d2 x h](https://www.tuli.si/media/custom/upload/LMK-UU-Linear-Bearings.pdf) — web — Publisher's page; dimensions are facts
- THK: [Linear bushings LM, LME, LMF: housing bore tolerances H7 / J7 / H6 / J6 / K6 and LM shaft tolerances f6 / g6 / h6 / f5 / g5 / h5 / h7 / k6 (B4-39 to B4-41)](https://tech.thk.com/en/products/pdf/en_b04_039.pdf) — web — Publisher's page; dimensions are facts
- McMaster-Carr: [Linear ball bearings and linear bearing shafts (rods) (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/products/linear-rod-bearings) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)
- McMaster-Carr: [Flange-mounted linear ball bearings (round and square flange, inch and metric) (free STEP/IGES per part, for your own design use; no redistribution)](https://www.mcmaster.com/flanged-linear-ball-bearings) — STEP, IGES, PDF — McMaster-Carr site terms: personal design use, no redistribution (verify at link)

## Questions

**What are the dimensions of an LM10UU?**

Bore 10, OD 19, length 29; ring grooves 1.3 wide at Ø18.

**What is the difference between LM8UU and LM8LUU?**

Same 8 mm bore and Ø15 OD; the L (long) is 45 mm long instead of 24 and carries a longer ball set.

**What snap ring groove does an LM8UU have?**

Groove 1.1 mm wide, groove diameter 14.3 (OD 15).

**How long is an LM12LUU?**

57 mm (OD 21, bore 12).

## Fits with

- [Flanged linear bushings LMF, LMK, LMH (and long LUU): bore, OD, length, flange size, bolt circle, hole + counterbore, 6 to 60 mm + STEP/STL (8 to 20 mm)](https://xemstudio.com/objects/flanged-linear-bushings-lmf-lmk-lmh/)
- [LM8UU linear bearing Ø8 × Ø15 × 24](https://xemstudio.com/objects/lm8uu-bearing/)
- [Linear shafts Ø3 to Ø25 mm (h6), 100 to 1000 mm long](https://xemstudio.com/objects/linear-shafts-h6/)
- [Pillow block KP08 envelope with a 608 pocket](https://xemstudio.com/objects/pillow-block-kp08/)
- [MGN9, MGN12 and MGN15 rails, 150 to 400 mm](https://xemstudio.com/objects/mgn-rails/)
- [Retaining rings DIN 472 (internal, for bores): ring dimensions and groove diameter d2 × width m, 8 to 110 mm](https://xemstudio.com/objects/retaining-rings-din-472-internal/)