# 624 bearing dimensions

A 624 bearing is 4 mm bore × 13 mm outside diameter × 5 mm wide (0.157 × 0.512 × 0.197 in). The sealed version is 624-2RS; the shielded version is 624-ZZ.

## 624 data

- Type: deep groove ball bearing, 62 series (light)
- Bore d: 4 mm (0.1575 in)
- Outside diameter D: 13 mm (0.5118 in)
- Width B: 5 mm (0.1969 in)
- Bore code: Under 10 mm bore the last digit is the bore itself: 4 = 4 mm
- Sealed: 624-2RS; shielded: 624-ZZ; open: 624

## Designations by maker

| Maker | Sealed | Shielded |
|---|---|---|
| SKF | 624-2RSH | 624-2Z |
| FAG (Schaeffler) | 624-2RSR | 624-2ZR |
| NSK | 624DDU | 624ZZ |
| NTN | 624LLU | 624ZZ |
| Koyo (JTEKT) | 624-2RS | 624ZZ |
| Timken | 624-2RS | see catalogue |


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

## FAQ

**What size is a 624 bearing?**
4 mm bore, 13 mm outside diameter and 5 mm wide, which is 0.157 × 0.512 × 0.197 in.

**What does 2RS mean on a 624 bearing?**
624-2RS has rubber contact seals on both sides. 624-ZZ (also written 624-2Z) has metal shields on both sides. Both have the same 4 × 13 × 5 mm dimensions.

**Is 624-2RS the same as 624-ZZ?**
They are the same size and interchangeable in a housing. The sealed 624-2RS keeps out fine dirt and water better; the shielded 624-ZZ runs with less friction.

**What is the SKF equivalent of 624-2RS?**
SKF writes it 624-2RSH; FAG 624-2RSR, NSK 624DDU, NTN 624LLU and Koyo 624-2RS. Check the maker's catalogue for the exact seal type.

**What does the number 624 mean?**
6 is the deep groove ball bearing type, 2 is the light dimension series, and under 10 mm bore the last digit is the bore itself: 4 = 4 mm.

Source page: https://machinistcharts.com/bearing/624/
Updated: 2026-10-06
Publisher: MachinistCharts (https://machinistcharts.com)