In mechanical processing, drilling is a common processing method, widely used in the hole processing of various metal and non-metal materials. However, in actual operation, drill bit breakage is one of the more common problems, which not only affects processing efficiency but may also lead to scrap of workpieces, equipment damage, or even safety accidents. Therefore, how to effectively avoid drill bit breakage is a skill that every operator and technician must master.



1. Select appropriate drill bit material and type



The material of the drill bit directly determines its hardness, wear resistance, and fracture resistance. Common drill bit materials include high-speed steel (HSS), carbide, coated drills, etc. For materials with high hardness, such as stainless steel, quenched steel, or cast iron, carbide or coated drills should be selected; for ordinary carbon steel or non-ferrous metals, high-speed steel drills can be used. In addition, appropriate drill bit types should be selected according to the workpiece material and processing requirements, such as spiral drills, center drills, deep hole drills, etc.



2. Reasonably set cutting parameters



Cutting parameters include cutting speed, feed rate, and cutting depth. Excessive cutting speed or feed rate can cause the drill bit to bear excessive cutting force and break. Generally speaking, the cutting speed should be adjusted according to the material hardness, and the feed rate should be selected based on the drill bit diameter and material toughness. When processing high-strength materials or deep holes, it is recommended to use a lower feed speed and intermittent feed method to reduce the load on the drill bit.



3. Ensure good cooling and lubrication conditions



A large amount of heat is generated during the drilling process. If cooling is insufficient, it can lead to overheat softening, increased wear, and even breakage of the drill bit. The use of appropriate cutting fluid can not only effectively cool down the drill bit but also improve the chip removal effect and reduce cutting resistance. In deep hole drilling, it is recommended to use a high-pressure internal cooling drill bit or adopt pulse cooling to ensure that the drill bit remains in good working condition.



4. Pay attention to the installation and alignment of the drill bit



Improper installation of the drill bit is also an important cause of breakage. The drill bit should be securely installed in the collet or handle to prevent loosening and eccentricity or vibration. At the same time, good centrality between the spindle and the workpiece must be maintained to avoid breakage of the drill bit due to uneven force caused by eccentric drilling.



5. Regular inspection and replacement of drill bits



The drill bit will gradually wear during use. A severely worn drill bit will dull the cutting edge, reduce the cutting performance, and easily lead to increased cutting force and breakage. Therefore, a regular inspection mechanism should be established to promptly discover worn or damaged drill bits and replace them.



6. Controlling vibration during the processing process



Vibration is one of the important causes of drill breakage. During the processing process, vibration should be minimized as much as possible, which can be achieved by selecting a rigid machine tool, using vibration reduction devices, and reasonably adjusting the fixture. At the same time, the feed should be slow at the beginning of drilling, and the feed force should be gradually increased after the drill bit stabilizes.



Conclusion



In summary, the key to avoiding drill breakage during drilling processing lies in selecting appropriate tools, reasonably setting cutting parameters, ensuring good cooling and lubrication, standardizing installation and operation, regular maintenance and inspection, and controlling vibration during the processing process. Only by paying close attention to each link can the service life of the drill bit be maximized, processing efficiency be improved, and production safety be ensured.