Nonmandrel bending’s primary objective is to bend tubing that would normally require some form of internal support without using that support. To achieve this goal, two factors are applied to the tube simultaneously during the bending process.
The diameter of the tube is reduced at the point of bend and the circumference of the tube is reshaped into a structural form for support.
When the tubing is a hard stainless steel, copper, or titanium, good bends can be achieved with a fairly generous structural shape. Soft tubing is much more difficult to control and may require a more radically-shaped tube groove.
After bending, the result is a piece of tubing that used to be round, but which has taken on a very new and distinctive shape during the bending process.
Nonmandrel bending is not the answer to all bending situations, nor has it reached its full potential. Its primary applications are found in the automotive and heating and air conditioning (HVAC) industries. Thoughtful engineering and creative manufacturing can create other applications appropriate for nonmandrel bending.