638 Bearing
Deep groove ball bearing
- Bore d8 mm
- Outer dia. D28 mm
- Width B9 mm
- Weight≈ 0.027 kg
High-speed applications such as electric motors, pumps, fans and gear reducers.
Technical data
| Bearing designation | 638 |
|---|---|
| Type | Deep groove ball bearing |
| Bore d | 8 mm |
| Outer dia. D | 28 mm |
| Width B | 9 mm |
| Weight | ≈ 0.027 kg |
Dimensions are standard catalogue values; the weight is an approximate calculation. Please confirm before ordering.
Common suffixes for 638
| 638 | Standard design (open, normal clearance) |
|---|---|
| 638-2RS | Rubber seals on both sides (sealed), greased |
| 638-ZZ | Metal shields on both sides (dust shields) |
Click a designation to open it in the bearing finder. Suffix usage can differ slightly between brands.
Matching seal (radial shaft seal)
8 × 28 × 7 mm
Seal weight: ≈ 6 g
Other common widths: 8 × 28 × 10 mm
The seal's inner diameter matches the shaft (8 mm) and its outer diameter matches the housing bore (28 mm); the width depends on the space in the housing. NBR (double lip, TC type) is recommended for general use and FKM (Viton) for high temperatures.
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