# Deep groove ball bearing (ISO 15)

Single-row deep groove ball bearing, metric: miniature 6xx and MR sizes, 60, 62, 63, 68 and 69 series up to a 50 mm
bore; open, shielded (ZZ / 2Z) or sealed (2RS); optionally with a flange on the outer ring (F623, F608, ...).

## Geometry

Envelope for assemblies and fits:

- one solid with the boundary dimensions: bore **d**, outside diameter **D**, width **B**;
- flat faces: shields and seals flush with the ring faces; balls, cage and the gap between the rings are not
  modelled (no catalogue dimension gives them);
- flanged: a flange of diameter **D1** and width **C1** on the outer ring, flush with the bottom face.

Centred on the origin, axis along Z, faces at z = ±B/2.

## Parameters

| Parameter | Meaning |
|---|---|
| `designation` | Basic bearing number: 623 … 629, 688, MR85, MR95, 6000 … 6010, 6200 … 6210, 6300 … 6310, 6800 … 6810, 6900 … 6910 |
| `closure` | `open`, `zz` (metal shields both sides), `2rs` (rubber seals both sides) |
| `flanged` | Flange on the outer ring (F623, F624, F625, F626, F608, F688 only) |

## Sources

- **Boundary dimensions d × D × B, per bearing number:** NTN, *Ball and Roller Bearings*, CAT. No. 2203-3/E (2024),
  pp. B-22 to B-27 (60, 62, 63, 68, 69 series) and B-48 to B-51 (miniature series: 623 … 629 (629 as 629X50), 688A,
  MR85 as 675, MR95 as BC5-9), <https://www.ntnglobal.com/en/products/catalog/pdf/2203E.pdf>. These are ISO 15:2017 boundary dimensions (*Rolling bearings — Radial
  bearings — Boundary dimensions, general plan*; preview with diameter series 7 and 8: <https://cdn.standards.iteh.ai/samples/69977/9ac39b8b79a94b74b35cba8868eabe4f/ISO-15-2017.pdf>, where 6800 … 6810,
  MR85 open and 688A (8 × 16 × 4) are checked directly); ISO 15 tabulates dimension series, not bearing numbers.
- **MR85, MR95**: NSK online product catalogue, *Extra Small Ball Bearings and Miniature Ball Bearings Metric Series*
  (<https://www.nsk.com/engineering/products/bearings/ball-bearings/deep-groove-ball-bearings/extra-small-ball-bearings-and-miniature-ball-bearings-metric-series/mr85-esm-md.html> and the MR85ZZ, MR95, MR95ZZ1 pages): MR85 5 × 8 × 2, MR85ZZ 5 × 8 × 2.5, MR95 5 × 9 × 2.5,
  MR95ZZ1 5 × 9 × 3. The shielded versions are wider than the open ones; sealed (2RS) widths aren't given, so MR85 /
  MR95 aren't offered with seals.
- **688:** NSK 688A 8 × 16 × 4 open (<https://www.nsk.com/engineering/products/bearings/ball-bearings/deep-groove-ball-bearings/extra-small-ball-bearings-and-miniature-ball-bearings-metric-series/688a-esm-md.html>), 688AZZ1, 688ADD and 688AVV 8 × 16 × 5; NTN p. B-50
  (688A open B 4, W688AZZ 5).
- **623, 624 sealed (2RS):** SKF 623-2RS1 3 × 10 × 4 and 624-2RS1 4 × 13 × 5, as listed by Simply Bearings
  (<https://www.simplybearings.co.uk/products/623-2rs1-skf>, <https://www.simplybearings.co.uk/products/624-2rs1-skf>);
  the 625 … 629 and 688 sealed widths from NSK's DD / VV item pages.
- **Flanges D1 × C1:** NSK online product catalogue, *… Metric Series With Flange*, items F623ZZ, F624ZZ, F625ZZ,
  F626ZZ1, F608ZZ (<https://www.nsk.com/engineering/products/bearings/ball-bearings/deep-groove-ball-bearings/extra-small-ball-bearings-and-miniature-ball-bearings-metric-series-with-flamge/f608zz-esm-md-wf.html>), F688A (D1 18, C1 1, open) and F688AZZ1 (18 × 1.1); NTN
  p. B-50 (FL688A C1 1.0 open, 1.1 shielded). The other flanges are the same open and shielded.

The model uses only these sourced dimensions: d, D, B, D1, C1.

| Designation | d | D | B (open) | B (ZZ / 2RS) | D1 × C1 |
|---|---|---|---|---|---|
| 623 | 3 | 10 | 4 | 4 | 11.5 × 1 |
| 624 | 4 | 13 | 5 | 5 | 15 × 1 |
| 625 | 5 | 16 | 5 | 5 | 18 × 1 |
| 626 | 6 | 19 | 6 | 6 | 22 × 1.5 |
| 627 | 7 | 22 | 7 | 7 | |
| 608 | 8 | 22 | 7 | 7 | 25 × 1.5 |
| 629 | 9 | 26 | 8 | 8 | |
| 688 | 8 | 16 | 4 | 5 | 18 × 1 (open), 18 × 1.1 (ZZ / 2RS) |
| MR85 | 5 | 8 | 2 | 2.5 (ZZ) | |
| MR95 | 5 | 9 | 2.5 | 3 (ZZ) | |
| 6000 … 6010 | 10 … 50 | 26 … 80 | 8 … 16 | same | |
| 6200 … 6210 | 10 … 50 | 30 … 90 | 9 … 20 | same | |
| 6300 … 6310 | 10 … 50 | 35 … 110 | 11 … 27 | same | |
| 6800 … 6810 | 10 … 50 | 19 … 65 | 5 … 7 | same | |
| 6900 … 6910 | 10 … 50 | 22 … 72 | 6 … 12 | same | |

Every row is in `part.py` (`BEARINGS`, `FLANGES`).

Not offered (no source for the dimensions): F6000, F6001 flanges; MR85-2RS, MR95-2RS.

Changed in 1.0.1: the face recesses (drawn depths and ring widths that no catalogue gives) are removed; the model is
the exact d × D × B envelope.

Corrected in this audit: 688 open width 5 -> 4 and the open F688 flange width 1.1 -> 1.0 (the shielded and
sealed 688 stay 5 wide with a 1.1 flange).

Preset list: designations of the step.parts catalogue (MIT), see `library/NOTICE.md`.