Summary of some methods to take off screws

1. You can use a grinder to grind the broken wire, and then use a small drill to drill first, and then gradually switch to a larger drill, the broken wire will gradually fall off, and then use the original size of the tap to re-tap the tooth. The advantage can be without increasing the aperture.

2. Weld an iron rod on the broken-in object, and then unscrew it. (Disadvantages: a. The cut-in is too small to be welded; b. It requires very high welding skills and is easy to burn the workpiece; c. The weld is easy to break, and the probability of taking out the broken-in is very small.)

3. Use a cone-shaped tool harder than the broken object to pry. (Disadvantages: a. Only suitable for brittle broken objects, break the broken objects into pieces, and then slowly remove them; b. The broken objects are too deep or too small to be taken out; c. The original hole is easy to damage.)

4. Make a hexagonal electrode smaller than the diameter of the broken-in object, use an EDM machine tool to machine a hexagonal counterbore on the broken-in object, and then unscrew it with an Allen key. (Disadvantages: a. Useless for rusty or stuck interrupted objects; b. Useless for large workpieces; c. Useless for too small interrupted objects; d. Time-consuming and troublesome.)

5. Directly use an electrode smaller than the cut-in object, and use an EDM machine to beat it. (Disadvantages: a. Useless for large workpieces and cannot be put into the EDM machine table; b. Time-consuming; c. When it is too deep, it is easy to deposit carbon and cannot be hit.)

6. Drill with an alloy drill bit (disadvantages: a, easy to destroy the original hole; b, useless for hard broken objects; c, alloy drill bit is more brittle and easy to break.) (Guide: choose metal parts to use triangle self-tapping Screw reason)

7. Now there is a portable machine tool designed and manufactured by the principle of electrical machining, which can easily and quickly take out the broken screw and broken tap drill bit.

8. If the screw is not too hard, you can flatten the end face, find the center point, punch a small point up with a sample, drill first with a smaller drill bit, be vertical, and then use a broken wire extractor Unscrew it in the reverse direction.

9. If you can't buy a broken wire extractor, use a larger drill bit to continue reaming. When the hole diameter is close to the screw, some of the wire will fall off with difficulty, remove the remaining threads, and then re-dress with a tap That's it.

10. If the broken wire of the screw is exposed, or the requirements for the broken screw are not strict, there is also a hand saw that can be sawed, you can saw the slit, even the shell, and then remove it with a flat-blade screwdriver.

11. If the broken wire is exposed to a certain length outside, and the melting point of the mechanical material is not too low, an extended T-shaped rod can be welded on the screw by electric welding, so that it can be easily unscrewed from the welded rod.

12. If the screw is very rusty and it is not easy to handle it with the above method, it is recommended to add a little lubricating oil after baking it red, and then use the corresponding method above.

13. After a lot of effort, although the screw is taken out, the hole is also useless at this time. Simply drill a larger hole and tap it. If the original screw position and size are limited, you can also use it. Go in with a larger screw, or directly weld and tap, and then drill a small hole in the center of the big screw to tap. However, the internal metal structure problem after welding is sometimes difficult to tap.

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