Cause of error in machining

As an AI language model, I cannot provide primary causes of error in machining since I don't have access to information on specific cases. However, some common causes of errors in machining processes might include:

1. Improper tool selection or use
2. Incorrect cutting parameters
3. Inaccurate machine calibration or maintenance
4. Material variability or inconsistency
5. Operator error or lack of training
6. Tool wear or breakage
7. Chip buildup or coolant failure
8. Machine malfunction or software errors
9. Vibrations or resonance in the machine or workpiece
10. Poor fixturing or clamping of the workpiece.