604 bearing
The 604 is a miniature ball bearing with a 4 mm bore, 12 mm outside diameter and 4 mm width, open (no seals or shields).
Size & specs
| Type | Miniature ball bearing |
|---|---|
| Bore (ID) | 4 mm (0.157 in) |
| Outside diameter (OD) | 12 mm (0.472 in) |
| Width | 4 mm (0.157 in) |
| Seals / shields | Open |
Cross reference: same bearing, other brands
| SKF | 604 |
|---|---|
| NTN | 604 |
| NSK | 604 |
| FAG | 604 |
| Timken | 604 |
| Koyo | 604 |
Budget brands usually sell this as 604. Add C3 if your old bearing was stamped C3 (looser fit for hot-running motors).
Where to buy
Other bearings with a 4 mm bore
Questions
What size is a 604 bearing?
4 × 12 × 4 mm (bore × outside diameter × width).
What is an open 604 bearing?
It has no seals or shields, so it must be lubricated by the machine (oil bath or grease). Choose 2RS or ZZ if the bearing needs to stay clean on its own.