# 6306 bearing dimensions

A 6306 bearing is 30 mm bore × 72 mm outside diameter × 19 mm wide (1.181 × 2.835 × 0.748 in). The sealed version is 6306-2RS; the shielded version is 6306-ZZ.

## 6306 data

- Type: deep groove ball bearing, 63 series (medium)
- Bore d: 30 mm (1.1811 in)
- Outside diameter D: 72 mm (2.8346 in)
- Width B: 19 mm (0.7480 in)
- Bore code: 06 × 5 = 30 mm (from 04 up, multiply by 5)
- Sealed: 6306-2RS; shielded: 6306-ZZ; open: 6306

## Designations by maker

| Maker | Sealed | Shielded |
|---|---|---|
| SKF | 6306-2RSH | 6306-2Z |
| FAG (Schaeffler) | 6306-2RSR | 6306-2ZR |
| NSK | 6306DDU | 6306ZZ |
| NTN | 6306LLU | 6306ZZ |
| Koyo (JTEKT) | 6306-2RS | 6306ZZ |
| Timken | 6306-2RS | see catalogue |

## Same 30 mm bore, other series

| Bearing | Series | OD mm | Width mm |
|---|---|---|---|
| 6806 | thin-section | 42 | 7 |
| 6906 | thin-section | 47 | 9 |
| 6006 | extra-light | 55 | 13 |
| 6206 | light | 62 | 16 |
| 6306 | medium | 72 | 19 |


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

## FAQ

**What size is a 6306 bearing?**
30 mm bore, 72 mm outside diameter and 19 mm wide, which is 1.181 × 2.835 × 0.748 in.

**What does 2RS mean on a 6306 bearing?**
6306-2RS has rubber contact seals on both sides. 6306-ZZ (also written 6306-2Z) has metal shields on both sides. Both have the same 30 × 72 × 19 mm dimensions.

**Is 6306-2RS the same as 6306-ZZ?**
They are the same size and interchangeable in a housing. The sealed 6306-2RS keeps out fine dirt and water better; the shielded 6306-ZZ runs with less friction.

**What is the SKF equivalent of 6306-2RS?**
SKF writes it 6306-2RSH; FAG 6306-2RSR, NSK 6306DDU, NTN 6306LLU and Koyo 6306-2RS. Check the maker's catalogue for the exact seal type.

**What does the number 6306 mean?**
6 is the deep groove ball bearing type, 3 is the medium dimension series, and 06 × 5 = 30 mm (from 04 up, multiply by 5).

**Which bearings have the same bore as 6306?**
6806, 6906, 6006, 6206 also have a 30 mm bore, with different outside diameters and widths.

Source page: https://machinistcharts.com/bearing/6306/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)