Cutting off bolts skillfully
2019-07-25
In the process of using bolts in construction, bolt breakage often occurs. Usually, maintenance workers use pliers to pull out the broken bolt from the broken part of the bolt in the opposite direction of the screw forward, or with the help of a broken bolt extractor, use a wrench to pull out the broken bolt.
Although the broken bolts can be removed by these methods, the uneven cross section of the bolts and the uneven torsion during operation can not be controlled, which will damage the threads of the bolt holes, resulting in the loose fitting of the newly installed bolts, leading to the breakage of the bolts again. Therefore, in practice, we have come up with a reliable method to remove the broken bolt without causing the thread deformation of the bolt hole. The specific operation methods are described as follows.
Firstly, a square iron is made by calculating the size of the square iron according to the diameter of the hole drilled on the broken bolt; the formula is alpha=R_2, then taking a section of round steel (according to the size of the actual broken bolt, the diameter is smaller than that of the broken bolt), drilling the inner hole (the diameter ratio of the inner hole) on the drilling machine. The broken bolt is small and made into a sleeve.
When taking the bolt, place the sleeve at the breaking position of the bolt, clamp it with the hand vise for easy operation, and then select a bit smaller than the sleeve made, and insert a hand electric drill into the borehole of the sleeve. (This drilling method is used to drill the borehole without deviating, without harming the thread of the bolt hole, and to control it evenly. Torsion twists out the broken bolt. After drilling, the broken bolt can be removed smoothly without damaging the threads by punching the hole with the square iron made in advance and then reverse twisting (with tool pliers).
