Mandrel Bending

Mandrel bending means simply bending pipes or tubes so there will be no kinks in the bend.  The type bends made by the typical bending machines you see in muffler shops are what we call "crush" bends because the bend is partially "crushed" while it is being made.  With a mandrel bending machine, a mandrel is inserted into the tube at the location of the bend while the bend is being made. 

Below are machines like those used to bend our tubes.  As you can see, they don't look like anything you see in muffler shops.  These babies cost $200,000 or more new.  The typical muffler shop bender cost $8 - $12,000.

This is one of the GM G-Body Monte SS Tails being bent.

This is a very simplified version of the mandrel bending process.  A long arm with a mandrel (sort of looks like a tool universal joint) on the end, is inserted in the far end of the tube and is placed appropriately in the bend while the machine does its thing.  Notice the tube is rotated in different directions before each bend is made.  What direction and how much depends on how the bender is programmed for the tube being bent.

This page last updated:  06/12/2010