There are some different technique in bending pipe and tube. Those are hot-slab forming, ram, roll, sand packing, rotary draw, and heat induction. The first method that used before those many different advanced techniques is ram pipe bending. Today, there are state of the art machineries that allow even steel tube bending easier and make better results. To make it precise, it even made computerized so the angle and diameter can be accurate.
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