Insufficient lubrication of CNC bearings: Insufficient or improper INA lubricating oil may cause component scratches or severe bearing deformation. Precautions: Improve the lubrication system and regularly replenish or replace the lubricant appropriately. Improper bearing operation: Improper installation, operation or disassembly of the bearing may cause deformation or defect of the cage. Precautions: Use appropriate operating, installation and removal tools. Bearing external materials: Abrasive particle contamination and debris intrusion may cause wear, scratches and depressions on the INA bearing working surface. Precautions: Remove intrusive particles and debris, replace lubricants, and check the sealing system. Bearing eccentricity: Eccentricity, tilt or excessive load may cause geometric stress concentration or surface flaking. Precautions: Use precision machined INA housings and shoulders.