Look around your home or car: you might not know it, but many of the pipes and tubes you see actually had to be manufactured in a specific way. Some good examples of these are plumbing pipes, automotive tubing, tubes in HVAC systems, and others around you. Even the pipes in the ground that transport water and waste were likely created using pipe and tube bending machinery.
There are many different types of tube bending and tube forming processes, such as mandrel tube bending, roll bending, heat induction, and others. Some processes that use tube bending dies also work to form the ends of the tubes and thread them (like the kind of threading you see on a screw. There are two ways to thread a pipe: on the inside of it or on the outside.
Tubes need to bend at very specific angles in order to function properly. Tube bending calculations must be very specific or else the tube will not form correctly, either. If the manufacturers don’t follow the tube bending formula required during the machine tooling process, then they won’t do what they are designed to do.
One of the more common types of tube bending processes is mandrel tube bending. A mandrel is a steel rod that is inserted into a tube in order to help it retain its shape, so it doesn’t break. Mandrel tube bending allows the tube to bend around the mandrel. A mandrel may be used on its own or in conjunction with another process.
Heat induction is one of these processes: the tube is heated to hundreds or even thousands of degrees in order to be shaped. Sand packing and hot slab forming are similar processes to heat induction. Roll bending inserts the tube among several dies and rolls in order to give it its shape and is similar to rotary draw bending for tubes.
Manufacturers who use these processes will sometimes use CNC machinery, which stands for computer numerical control and means that the machine is controlled through automated processes by computer. CNC tube bending machines are generally used in factories and large shops only — they’re not something you’d find for sale in your average home improvement store. Without these machines and manufacturers, however, we wouldn’t have many of the products we see around us today.