The tap and drill are broken in the hole. How to fix it?

  1. Fill it with lubricating oil and slowly knock it out on the fracture surface in the opposite direction with a sharp tassel(The most common method in the shop, but may not be suitable for threaded holes with too small diameter or for broken taps that are too long).
  1. Weld a handle or hex nut on the broken section of the tap, and then gently reverse it (it is a good method, but welding is a bit troublesome, it has samesituation, it is not suitable for threaded holes with too small diameter)
  1. Special tools: broken tap extractor, the principle is that the workpiece and tap are connected with positive and negative electrodes, the middle of the electrolyte, resulting in the discharge of the workpiece to the tap corrosion, and then use auxiliary needle-nosed pliers to remove the broken tap, this method does little damage to the inner hole.
  1. Take the top of the steel roller to crack the tap with a small hammer, tapis brittle, and finally knock slag out.
  1. Weld the threaded hole where the broken tap is located, grind it again, and re-drill. Although it is difficult, you can slowly drill in.
  1. Cut a slot in the cross section of the broken tap and use a screwdriver to reverse it (the slot is difficult to cut, and it is even more difficult if the tap diameter is small).
  1. Drilling the threaded hole of the broken tap large, then inlaying athread insert or pin, and then welding, smoothing, re-drilling and tapping can be basically the same (this method is troublesome, but very practical).
  1. Use electric pulse to knock it off, electric spark or wire cutting can be used, if the hole is damaged, you can expand the hole and add a thread insert.
  1. Make a simple tool and insert it into the chip slot of the broken tap cross section. Carefully pull it out in the opposite direction.
  1. Nitric acid solution can corrode high-speed steel tapwithout scrapping the workpiece.
  1. Use an acetylene flame or torch to anneal the tap, and then use a drill to drill. At this time, the diameter of the drill should be smaller than the diameter of the bottom hole. The hole should also be aligned to the center to prevent the thread from being damaged.After the hole is drilled, drive a flat or square punch and then screw out the tap with a wrench.
  1. Use the air drill to reverse the tap, depending on the handfeeling, because instead of drilling the tap off, you use a slow speed and a little friction (like a car half clutch) to get the tap out.
  1. You can use a grinder to smooth the broken tap, then use a small drill bit to drill first, and then gradually use a larger drill bit, the broken tapgradually falls off, and after the fall, use the original size tap to re-tap the thread. This advantage can be No need to increase the aperture.
  1. Weld an iron rod to the broken tap or drilland then unscrew it. (Disadvantages: too small broken objects can not be welded; extremely high welding skills are required, and it is easy to burn the workpiece)
  1. Pry with a tapered tool that is harder than the broken object. (Disadvantages: only suitable for brittle broken object, it is easy to damage the original hole)
  1. Hit with an alloy bit (disadvantages: easy to damage the original hole; useless for hard broken object; alloy bit is more brittle and easy to break)
  1. There is a portable machine tool designed and manufactured based on the principle of electromachining, which can easily and quickly remove broken tap and drill.
  1. If the tapis not too hard, you can flatten the end face, find the center point, use a smaller drill bit to drill vertically, and then use the broken tap remover to unscrew it.
  1. If you cannot buy the broken wire extractor, use a larger drill to continue the reaming. When the hole diameter is close to the tap, some of the wire willfall off. Remove the remaining threads and then reshape them with a tap.
  1. If the broken wire of the screw is exposed, or the requirements of the broken screw are not strict, you can saw it with a saw blade, and even the shell, then remove it with a flat-blade screwdriver.
  1. If the broken wire is exposed to a certain length and the melting point of the mechanical material is not too low, an elongated T-shaped rod can be welded on the screw by electric welding, so that it can be easily unscrewed from the welded rod.
  1. If the rust of the screw is very serious, it is difficult to handle with the above method, it is recommended to add a little lubricating oil after baking with fire, and then use the corresponding method above.