
Remember how in one of the Russian folk tales bear arc bent? Took two legs of the barrel at both ends and through the knee. For while it attempts, as we know, was not successful, note that to perform this operation, in modern technical language, it took him three working “element”: one rounding (knee) and two power (paws). The most modern devices for bending tubes and bars contain the same three elements. Usually they are mounted on a special table. There is a metal loop, which is inserted into one end of the pipe, a stationary roller — on it is bent, and the movable roller with the lever.
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