A part of the mandrel assembly which supports the arc of the bend from flattening along the outside radius after the tubing material has passed through the point of bend. The term ball is derived from the fact that geometrically it is the center segment of a true sphere; this is why a ball is occasionally called a “sphere” or “segment”. Because of its spherical geometry, as opposed to the cylindrical geometry of the mandrel nose, the ball is not very effective in setting the tubing material into a circular cross-section at the point of bend. For this reason, the mandrel should be fixtured so that the entire ball, or balls, rests past the point of bend — not in the point of bend or behind it.
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.