# 6903 bearing dimensions

A 6903 bearing is 17 mm bore × 30 mm outside diameter × 7 mm wide (0.669 × 1.181 × 0.276 in). The sealed version is 6903-2RS; the shielded version is 6903-ZZ.

## 6903 data

- Type: deep groove ball bearing, 69 series (thin-section)
- Bore d: 17 mm (0.6693 in)
- Outside diameter D: 30 mm (1.1811 in)
- Width B: 7 mm (0.2756 in)
- Bore code: 03 = 17 mm (codes 00 to 03 are fixed: 10, 12, 15 and 17 mm)
- Sealed: 6903-2RS; shielded: 6903-ZZ; open: 6903

## Designations by maker

| Maker | Sealed | Shielded |
|---|---|---|
| SKF | 6903-2RSH | 6903-2Z |
| FAG (Schaeffler) | 6903-2RSR | 6903-2ZR |
| NSK | 6903DDU | 6903ZZ |
| NTN | 6903LLU | 6903ZZ |
| Koyo (JTEKT) | 6903-2RS | 6903ZZ |
| Timken | 6903-2RS | see catalogue |

## Same 17 mm bore, other series

| Bearing | Series | OD mm | Width mm |
|---|---|---|---|
| 6803 | thin-section | 26 | 5 |
| 6903 | thin-section | 30 | 7 |
| 6003 | extra-light | 35 | 10 |
| 6203 | light | 40 | 12 |
| 6303 | medium | 47 | 14 |


Load ratings and speed limits vary by maker: take them from the manufacturer's catalogue.

## FAQ

**What size is a 6903 bearing?**
17 mm bore, 30 mm outside diameter and 7 mm wide, which is 0.669 × 1.181 × 0.276 in.

**What does 2RS mean on a 6903 bearing?**
6903-2RS has rubber contact seals on both sides. 6903-ZZ (also written 6903-2Z) has metal shields on both sides. Both have the same 17 × 30 × 7 mm dimensions.

**Is 6903-2RS the same as 6903-ZZ?**
They are the same size and interchangeable in a housing. The sealed 6903-2RS keeps out fine dirt and water better; the shielded 6903-ZZ runs with less friction.

**What is the SKF equivalent of 6903-2RS?**
SKF writes it 6903-2RSH; FAG 6903-2RSR, NSK 6903DDU, NTN 6903LLU and Koyo 6903-2RS. Check the maker's catalogue for the exact seal type.

**What does the number 6903 mean?**
6 is the deep groove ball bearing type, 9 is the thin-section dimension series, and 03 = 17 mm (codes 00 to 03 are fixed: 10, 12, 15 and 17 mm).

**Which bearings have the same bore as 6903?**
6803, 6003, 6203, 6303 also have a 17 mm bore, with different outside diameters and widths.

Source page: https://machinistcharts.com/bearing/6903/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)