Single-row ball and crossed-roller bearings are the two most common slewing ring designs. Both carry axial, radial and moment loads in one bearing, but they behave very differently under load, and choosing the wrong one costs either money or performance.
Single-row ball slewing rings
One row of steel balls runs between the inner and outer rings, usually with four-point contact, so the bearing carries axial load, radial load and tilting moment together.
- Versatile: handles combined loads in all directions.
- Cost-effective: simpler construction, lower cost to make and replace.
- Compact and easy to service.
Use one when loads are moderate, cost matters, and very high stiffness or accuracy is not required. Typical uses: cranes and small excavators, turntables, wind turbines, food processing and packaging machines.
SlewPro series: 21 Series (light "L"-section) and 30 Series (medium to heavy duty). For more on the design, see inside the single-row ball slewing bearing.
Crossed-roller slewing rings
Cylindrical rollers run between the raceways with each roller at right angles to the next, in a crisscross pattern. Line contact instead of point contact makes the bearing much stiffer and more accurate.
- Higher rigidity: very little deflection under load.
- Higher accuracy: low clearance for precise positioning.
- High capacity for axial, radial and moment loads.
Use one when rigidity and accuracy are critical, the load reverses or changes direction often, backlash and vibration must be minimized, or capacity matters more than cost. Typical uses: robotics and automation, machine tools, medical imaging such as CT scanners, aerospace and defense.
SlewPro series: 50 Series. Before you specify one, read 5 ways engineers misapply cross roller bearings.
Side by side
| Feature | Single-row ball | Crossed roller |
|---|---|---|
| Load capacity | Moderate | High |
| Stiffness | Moderate | Very high |
| Accuracy | Moderate | High |
| Cost | Lower | Higher |
| Maintenance | Easier | More demanding |
| Typical use | General industry | High-precision machinery |
Still not sure?
The right choice depends on the load direction and size, the accuracy you need, the space and the budget. If neither fits, a double-row ball bearing or a triple-row roller may. Replacing an existing bearing? Find its SlewPro equivalent. Otherwise, send us your loads and our engineers will recommend one.