On Thu, 24 Mar 2011 18:58:46 -0400, Wes
wrote:
snip
That handle doesn't look like it was bent on a standard EMT bender. Look at the pdf
http://www.princecastle.com/docs/CC-CM.PDF

It looks like they have a formed arch in the inner radius to give the handle strength.
snip
This is what is generically called "crush" bending.
Generally this allows a smaller radius bend and the material
on the inside of the bend does not have to be compressed as
much, although there may be some increase. I think the
Gingery dies could be modified to do crush bending by
including a rib or ridge on the center of the inside die
[make in three pieces?].

http://www.bendtooling.com/c-d.htm
snip
crush bending — A non-mandrel method of bending in which the
compression of the intrados is controlled by stretching it
over a "crush knob" seated in the cavity of the bend die.
This eliminates the wrinkling or buckling that might occur
if the tube were bend without a mandrel. Commonly used on
non-round tube bends.

crush knob — A raised section of a bend die cavity over
which the intrados is stretch to alleviate the compression,
thus eliminate wrinkling and buckling.
snip

http://www.hinesbending.com/BASICTUBEBENDINGGUIDE.pdf
{see pages 17/18}





-- Unka George (George McDuffee)
...............................
The past is a foreign country;
they do things differently there.
L. P. Hartley (1895-1972), British author.
The Go-Between, Prologue (1953).