Pipe benders give the craftsmen the ability to bend pipes and conduits.
Simple pipe benders worked by hand are generally for a fixed radius and a specific diameter of pipe. The pipe is fitted into the bender so that the apex of the bend is aligned with an arrow on the pipe bender. The pipe bend is usually created by pulling the bender handle through the necessary angle while you use a foot pedal to stop the bender slipping. Bends produced in this way suffer some distortion. The pipe will be weakened but still suitable for carrying water or gas.
Rotary Draw Benders
These machines are among the best for pipe bending because the pipe is drawn through two dies by a third to create the correct amount of bend. There is still some distortion at the bend but the strength is sufficient for construction purposes. Sometimes a mandrel is used with rotary draw benders to prevent some of the distortion but the general feeling is that they reduce the strength of the bend.
The best pipe benders are rotary draw. benders. You need to ensure that you purchase a set of dies for each radius of tube you are going to bend as well as a full set of instructions.