A physically active section of the tube during the bending process as opposed to an idealized geometrical element. The point of bend, intrados, extrados, and neutral axis are the primary regions of the tube. Compare geometry. (See diagram under that entry for illustration of regions.)
FREE Tube-Bending Guide Download:
A complete guide to the principles of the 4-Step set-up for tube-bending tools
This is a printable handbook showing how to implement in four standardized steps the “forward mandrel” set-up for rotary-draw tube-bending machines and establish process control over the so-called black art. The procedure is based upon the guiding principle that the tools make the bend and takes advantage of the inserted design of modern mandrel tooling.