William Q. Tingley

Not all draw bending applications in a tube fabrication shop require a mandrel, a wiper, or the pressure die assist feature. However, understanding each of them can help a fabricator troubleshoot problems more accurately and quickly and determine the need for one of these if it is absent.

Setting the grip die securely in rotary draw bending requires close attention to three factors: the pressure exerted by the machine, the contact area, and the material’s coefficient of friction.