20 Ways to Solve the Tap Breakage During CNC Lathe Machine Tapping

1. Add lubricating oil to the broken part of the tap, use a sharp hairpin or something that can bear the force, and gradually knock it out on the reverse side of the broken, don’t forget to pour the iron frequently (this method is commonly used in the workshop, but if the aperture is too small threaded holes or broken taps are too long to fit, but can be tested).

2. Weld a handle or a hexagonal nut on the broken section of the tap, and then slowly turn it back out (this method is a good way, but welding is sometimes inconvenient, if the hole diameter is too small for threaded holes or broken taps too long to be suitable).

3. Use special equipment: broken tap extractor. The principle is that the two ends of the workpiece and the tap are connected to positive and negative electrodes respectively, and the electrolyte is poured into the hole, so that the workpiece discharges to the tap to corrode the broken tap, and then use a sharp tip. The vise is slowly taken out in reverse, this method does little damage to the inner hole.
4. Hold the steel rod against the crack of the tap and tap it directly with a small hammer. Since the tap is relatively brittle, slowly knock the tap into slag, or use the simplest method to directly drill the threaded hole of the broken tap with a drill bit. Or boring, re-reaming and tapping (the method is a bit rough, if the diameter of the tap is too small, it is not ideal, and the diameter is too large, it is also very hard to tap).

5. Weld the threaded hole of the broken tap flat, then grind it flat, and re-drill it. Although it is difficult, it can gradually be drilled in (if the threaded hole can be changed in orientation, when re-drilling and tapping, it is recommended to change to around the original threaded hole).

6. At the broken tap, chisel a slot on the cross-section and screw it up with a screwdriver in reverse (that slot is difficult to chisel out, and it is even more difficult if the diameter of the tap is small)

7. Drill the threaded hole of the broken tap to a larger size, then insert a wire screw sleeve or pin or something, then weld, grind it flat, and re-drill and tap, which can be the same as the original size (although this method is troublesome, But it’s very useful, it doesn’t matter how much the tap size is).

8. Destroy it with electric pulse, electric spark or wire cutting. If the hole is damaged, you can ream the hole and add a wire screw sleeve (this method is easier, as for the coaxiality, don’t consider it for the time being, unless your threaded hole is coaxial degree directly affects the quality of the equipment).

9. Make a common thing to pierce the chip removal groove of the broken tap section, and carefully pull it out in reverse. For example, you can use a broken tap with a square tenon to screw 2 nuts, and use steel wires (the number is the same as the number of tap grooves) Pierce into the empty groove of the broken tap and the nut, and then use the hinge rod to pull the square tenon in the exit direction to take out the broken tap (the main idea of ​​this method is to connect the chip groove of the broken tap, and use steel wire, preferably The steel needle is used to make a wrench specially designed to remove broken wires. Of course, if such broken wires often occur in the workshop, it is better to make such a wrench).

10. The nitric acid solution can corrode the high-speed steel tap, and will not cause damage to the workpiece and scrap the workpiece.

11. Anneal the tap with an acetylene flame or a blowtorch, and then drill it with a drill bit. At this moment, the diameter of the drill bit should be smaller than the diameter of the bottom hole, and the drill hole should be aligned with the center to avoid damaging the thread. Use a wrench to unscrew the tap from the square punch.

12. Rotating with an air drill depends entirely on the feel. Because the tap is not drilled directly, but a slow speed and a little friction (similar to the semi linkage of a car) are used to turn the tap out.

13. You can use a grinder to smooth the broken wire, and then use a small drill to drill first, and then gradually switch to a larger drill. The advantage of this is that it is possible not to have to increase the aperture.

14. Weld an iron rod on the fault and screw it out. (Defects: a. Too small broken objects cannot be welded; b. Very high welding skills are required, and the workpiece is easily burned; C. The welding place is easily broken, and the probability of taking out the broken objects is very small.)

15. Pry with a cone-shaped object that is harder than a tap. (Defects: a. Only suitable for brittle taps, smash the taps, and then gradually remove them; b. The taps are too deep and too small to be taken out; C. It is easy to damage the original holes.)

16. Make a hexagonal electrode smaller than the diameter of the tap, use an EDM machine to machine a hexagonal counterbore on the tap_, and then screw it out with an Allen wrench. (Defects: a. Useless for rusted or stuck taps; b. Useless for large workpieces; C. Useless for taps that are too small; d. Time-consuming and troublesome.)

17. Directly use the electrode smaller than the tap, and use the EDM machine to hit. (Defects: a. It is useless for large workpieces and cannot be put into the EDM machine table; b. Time-consuming; C. It is easy to deposit carbon when it is too deep, and it cannot be played.)

18. Use an alloy drill bit (defects: a. It simply damages the original hole; b. It is useless for hard broken objects; c. The alloy drill bit is brittle and easy to break.)

19. Now there is a portable tool designed and manufactured by the principle of electric processing, which can easily and quickly remove broken screws and broken tap drill bits.

20. If the screw is not too hard, the end face can be flattened, and then find the center point, punch a small point with the sample punch, drill first with a smaller drill bit, make it straight, and then use the broken wire extractor to reverse it. out.