Precision machine tool angular contact ball bearings typically have the following characteristics:

1. High precision: This type of bearing design is used for precision machine tool applications and therefore has high precision, providing stable operation and precise position control.

2. High speed: Angular contact ball bearing designs can provide lower friction and better rotational smoothness at high speeds, making them suitable for machine tool applications that require high speeds.

3. High load capacity: These bearing designs can withstand large radial and axial loads, ensuring that the machine tool can withstand various forces from the machining process during operation.

4. High rigidity: Angular contact ball bearings are typically designed as double or quadruple structures, which provide better rigidity and stability, helping to reduce vibration and deformation and thereby improve machine tool accuracy.

5. Lubrication method: To ensure long-term operation of the bearing under high-speed and high-load conditions, lubricating oil or grease is usually used to maintain the bearing's good lubrication status.

6. Sealing design: Some precision machine tool angular contact ball bearings are also equipped with sealing devices to prevent external contaminants from entering the bearing and maintain its operational stability and lifespan.