The extension of the bend die cavity past the vertical centerline of the tube which is the defining feature of the captive-lip cavity design. The typical length of this lip is 6% of the tube diameter. The no-lip cavity design is actually a negative lip; the mating face of the cavity is relieved from the vertical centerline of the tube usually by 1% of the tube diameter.
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.