Deep Groove Ball Bearings: A Complete Engineering Guide
Key Takeaways
- Deep groove ball bearings handle radial, axial and combined loads at high speeds.
- The last two digits of the part number × 5 = bore in mm (6205 = 25mm bore).
- 2RS seals for dusty/wet environments, ZZ for clean high-speed, Open for relubrication.
What is a deep groove ball bearing?
A deep groove ball bearing is the most widely used rolling bearing in the world. Its raceway grooves are deeper than the ball radius, allowing the bearing to support radial loads, axial loads in both directions, and combined loads at relatively high speeds. The simple, symmetrical design makes it inexpensive, reliable and easy to fit.
How they work
Load is transferred from the inner race to the balls and then to the outer race. Because the balls roll rather than slide, friction is low and speeds are high. The deep raceway geometry lets the balls stay seated under combined radial and axial loading without ejecting.
Choosing the right size
Standard deep groove ball bearings are identified by a 4-digit part number (the 62XX and 63XX series are most common). The last two digits multiplied by 5 give the bore in millimetres — so a 6205 has a 25 mm bore. The first digit indicates the width series; the second the diameter series. Always confirm the bore, outer diameter and width against a datasheet before ordering.
Choosing the right seal
- 2RS — two rubber seals, lubricated for life. Best for dusty or moist environments and most general use.
- ZZ — two metal shields. Lower friction and higher speed, but less moisture protection.
- Open — no seals. Maximum speed and easy relubrication for clean, lubricated environments.
Common applications
Deep groove ball bearings are found in electric motors, fans, pumps, conveyors, household appliances, agricultural machinery and automotive ancillaries wherever moderate loads and high speeds are expected.
Why buy from Buy Bearings
We stock 17,000+ deep groove ball bearings from ISB, SKF and FAG with next-day UK delivery. The full ISB Bearings range is held in stock, backed by full technical support and competitive POA pricing — submit an enquiry and our team responds within one hour during business hours.
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Frequently Asked Questions
What does the number on a deep groove ball bearing mean?
The last two digits multiplied by 5 give the bore in millimetres. A 6205 bearing has a 25 mm bore. The first digit is the width series and the second the diameter series.
Can a deep groove ball bearing take axial load?
Yes. Deep groove ball bearings support axial loads in both directions as well as radial loads, which is one reason they are so widely used.
Should I choose 2RS or ZZ?
Choose 2RS for dusty, moist or general environments where relubrication is unwanted. Choose ZZ for clean, high-speed applications where lower friction matters more than moisture protection.
Need help choosing a bearing?
Our engineers can identify the right part from a number, dimensions or a competitor reference.