1. The drill bit should be packed in a special packing box to avoid vibration collision.

2. When in use, the drill bit taken out of the packing box shall be loaded into the collet chuck of the spindle or the tool magazine for automatically replacing the drill bit.  Put it back into the packing box immediately after using it.

3. Non-contact measuring instruments such as a tool microscope shall be used to measure the diameter of the drill bit, so as to avoid the cutting edge from being damaged due to contact with the mechanical measuring instrument.

4. Some numerical control drilling machines use positioning rings. Some numerical control drilling machines do not use positioning rings. For example, the depth positioning when installing the positioning rings must be accurate. For example, the extension length of the drill bit installed on the main shaft should be adjusted to be consistent without using positioning rings. More attention should be paid to this point for multi-spindle drilling machines, and the drilling depth of each main shaft should be consistent.  If there is inconsistency, the drill bit may drill to the table top or cannot drill through the circuit board, resulting in scrapping.

⒌ At ordinary times, a 40-fold stereo microscope can be used to check the wear of the cutting edge of the drill bit.

6. Always check the concentricity of the main shaft and the collet chuck and the clamping force of the collet chuck. Poor concentricity will cause small diameter drill bits to break and have large bore diameter. Poor clamping force will cause the actual rotating speed to be inconsistent with the set rotating speed and slip between the collet and the drill bit.

7. The clamping length of the fixed shank drill bit on the collet chuck is 4 ~ 5 times of the diameter of the drill shank to clamp firmly.

8. Always check the spindle presser foot.  The contact surface of the presser foot should be horizontal and vertical to the main shaft without shaking, so as to prevent broken and deviated holes from occurring in the drilling.

9. The dust absorption effect of drilling machine is better. The dust absorption air can reduce the temperature of drill bit and take away dust to reduce the high temperature caused by friction.

⒑ The base plate stack includes upper and lower base plates to be firmly positioned and leveled in a hole-and-groove positioning system on the workbench of the drilling machine.  When using adhesive tape, it is necessary to prevent the drill bit from sticking chips on the tape, causing chip removal difficulties and drill breakage.

11. When ordering drill bits from manufacturers, 4% of them shall be checked for compliance when entering the factory for inspection.  And 100% of them were examined for nicks, scratches and cracks with 10-15 times the microscope.

When the diameter of the drill bit is reduced by 2% compared with the original due to wear, the drill bit is scrapped.

⒓ Setting of drill bit parameters Under normal circumstances, manufacturers provide a parameter table of the drilling speed and down speed of drill bits produced by the factory. This parameter is only for reference. In practice, technicians are required to obtain a drill bit speed and down speed parameter that meets the actual conditions through actual use. Usually, the actual parameters are different from the reference parameters but the difference is not too great.

13. When sharpening the drill bit, the two main cutting edges of twist drill should be sharpened symmetrically as far as possible so that the radial forces of the two main cutting edges cancel each other out to prevent the drill bit from deflecting and the hole diameter from expanding.