A ball sub-assembly, which see, plus a mandrel nose insert. A one-ball mandrel sub-assembly includes the following components:  mandrel nose insert,  insert link,  mandrel ball, and  end link. Multiple-ball mandrel sub-assemblies include a mandrel and a center link for each additional ball of the assembly.
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.