Material
Bearing 691 is typically made of high - grade chrome steel, such as AISI 52100. This material is well - known for its excellent mechanical properties. It has high hardness, which enables the bearing to withstand heavy loads and resist wear during long - term operation. Chrome steel also offers good toughness, reducing the risk of fracture when the bearing is subjected to impact or sudden loads. Additionally, it can be heat - treated to further enhance its strength and durability, ensuring that the bearing maintains stable performance even in demanding working conditions. The inner ring, outer ring, balls, and cage (if present) of the 691 bearing are all manufactured from this chrome steel, providing a consistent and reliable structure.
Design Features
The 691 bearing adopts a deep - groove ball design, which is a common and effective design in the bearing industry. The deep - groove raceways in both the inner and outer rings are precisely machined to allow the balls to roll smoothly, ensuring low friction during operation. This design enables the bearing to handle both radial and axial loads, although it is more effective at bearing radial loads. With a bore diameter of 1.5 mm, an outer diameter of 4 mm, and a width of 1.3 mm, the 691 bearing is designed to fit into small - space applications. It has a lightweight construction, weighing approximately 0.06 g, which is beneficial for reducing the overall weight of the equipment it is installed in. The bearing is usually available in an open configuration, which allows for easy lubrication and inspection. However, in environments with a lot of dust or debris, sealed versions may also be available to protect the internal components.
Applications
1. Household Appliances: Bearing 691 is widely used in small household appliances. For example, in electric shavers, it helps the cutting heads rotate smoothly, ensuring a comfortable and efficient shaving experience. It is also found in small fans, where it enables the fan blades to spin at high speeds, providing effective air circulation.
2. Office Equipment: In office equipment such as printers and scanners, the 691 bearing is used in the paper - feeding mechanisms and the rotating parts of the scanning heads. Its precise rotation ensures accurate paper feeding and clear scanning results.
3. Toys and Models: Many toys and models, such as remote - controlled cars and model airplanes, rely on the 691 bearing. It allows the wheels, propellers, and other moving parts to rotate freely, enhancing the performance and playability of the toys and models.
4. Precision Instruments: In some small - sized precision instruments, like certain measuring tools and gauges, the 691 bearing is used to ensure the accurate rotation of the instrument components, contributing to the precision of measurements.
| Part Number | 691 |
| System of Measurement | Metric |
| Bearing Type | Ball |
| For Load Direction | Radial |
| Construction | Single Row |
| Inner Ring Type | Standard |
| Seal Type | Open |
| Bore Dia | 1 mm |
| Bore Dia Tolerance | -0.008mm to 0 |
| Outer Dia | 4 mm |
| Outer Dia Tolerance | -0.008mm to 0 |
| Width | 1.6 mm |
| Width Tolerance | -0.12mm to 0 |
| Ring Material | Chrome Steel |
| Ball Material | Chrome Steel |
| Cage Material | Carbon Steel |
| Dynamic Radial Load | 27 lbf |
| Static Radial Load | 7 lbf |
| Max Speed (X1000 rpm) | 100 |
| Lubrication | Required |
| Temperature Range | -30° to 110 °C |
| Tolerance Class | ABEC1 |
| Radial Clearance Trade No | MC3 |
| Radial Clearance | 0.005mm to 0.01 mm |
| RoHS | Compliant |
| REACH | Compliant |
| Ball Dia | 0.8 mm |
| Ball Qty | 5 |
| Weight | 0.11 g |
