# 6309 bearing dimensions

A 6309 bearing is 45 mm bore × 100 mm outside diameter × 25 mm wide (1.772 × 3.937 × 0.984 in). The sealed version is 6309-2RS; the shielded version is 6309-ZZ.

## 6309 data

- Type: deep groove ball bearing, 63 series (medium)
- Bore d: 45 mm (1.7717 in)
- Outside diameter D: 100 mm (3.9370 in)
- Width B: 25 mm (0.9843 in)
- Bore code: 09 × 5 = 45 mm (from 04 up, multiply by 5)
- Sealed: 6309-2RS; shielded: 6309-ZZ; open: 6309

## Designations by maker

| Maker | Sealed | Shielded |
|---|---|---|
| SKF | 6309-2RSH | 6309-2Z |
| FAG (Schaeffler) | 6309-2RSR | 6309-2ZR |
| NSK | 6309DDU | 6309ZZ |
| NTN | 6309LLU | 6309ZZ |
| Koyo (JTEKT) | 6309-2RS | 6309ZZ |
| Timken | 6309-2RS | see catalogue |

## Same 45 mm bore, other series

| Bearing | Series | OD mm | Width mm |
|---|---|---|---|
| 6809 | thin-section | 58 | 7 |
| 6909 | thin-section | 68 | 12 |
| 6009 | extra-light | 75 | 16 |
| 6209 | light | 85 | 19 |
| 6309 | medium | 100 | 25 |


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

## FAQ

**What size is a 6309 bearing?**
45 mm bore, 100 mm outside diameter and 25 mm wide, which is 1.772 × 3.937 × 0.984 in.

**What does 2RS mean on a 6309 bearing?**
6309-2RS has rubber contact seals on both sides. 6309-ZZ (also written 6309-2Z) has metal shields on both sides. Both have the same 45 × 100 × 25 mm dimensions.

**Is 6309-2RS the same as 6309-ZZ?**
They are the same size and interchangeable in a housing. The sealed 6309-2RS keeps out fine dirt and water better; the shielded 6309-ZZ runs with less friction.

**What is the SKF equivalent of 6309-2RS?**
SKF writes it 6309-2RSH; FAG 6309-2RSR, NSK 6309DDU, NTN 6309LLU and Koyo 6309-2RS. Check the maker's catalogue for the exact seal type.

**What does the number 6309 mean?**
6 is the deep groove ball bearing type, 3 is the medium dimension series, and 09 × 5 = 45 mm (from 04 up, multiply by 5).

**Which bearings have the same bore as 6309?**
6809, 6909, 6009, 6209 also have a 45 mm bore, with different outside diameters and widths.

Source page: https://machinistcharts.com/bearing/6309/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)