View Full Version : Making tube bending dies?

10-13-2008, 06:07 PM
I am thinking about making my own tube bending dies and bender. I am wanting to build a set of dies for 1", 1.25", 1.5" & 2". I would like to bend exhaust and steel tube .125 wall and less roll bar frame type stuff maybe some schd 40 Al.

I was thinking of making the dies from CR round stock from 5" & 6" stock or what ever I can get my hands on that would machine easily. I do not have CNC on my mill so I was thinking of doing it on the lathe and using a ball turner to make the concave profile on the die.

The bender would be a Protools or JD2 type bender. This will be for a home shop so the dies will not see daily production use so I was thinking mild steel or cold rolled would do for die material.

Dose this seem feasable?

Thanks Mike

10-13-2008, 08:09 PM
Yup,very doable and I have used more than one Greenlee ridgid conduit bender that used cast aluminum dies.No real need for steel if your doing a few bends once and awhile.

I had somewhere a link to a site where the mfg gave cad drawings for their dies.The minimum bend radius is the important number.2" tubing in an open die is a fairly good sized radius,close to 8" IIRC.

10-13-2008, 08:48 PM
I have a Pro Tools 1" die for a bender I've made (a gottrikes.com bender) and I've thought of making some extra dies. New dies from Pro Tools are a couple hundred each (with shipping) so I figure it's worth making one. The plans from gottrikes.com include dimensions for a 1" x 3.5" radius die and follower as well as a 1" x 5" radius square tubing die and follower.

Mike Burdick
10-13-2008, 09:15 PM

Here is a die that I made for 2" rigid pipe with a 12-inch radius bend. It's made from built up 1/4" plate steel fastened together with 1/2-inch bolts. I cut each piece out with a band saw and, after assembly, I ground the high edges down with an 4.5" hand grinder. This went surprisingly fast since each "low" side could be used for a guide. Cutting out the plates and grinding them down took about 2 hours from start to finish. For perspective, the ridge on each side is 1/2-inch in width.

This turned out to be very inexpensive since each plate pattern could be arranged on the plate steel so very little waste occurred. Matter of fact, one could go to a steel fabricating shop and buy their small scraps for very little.

So... to answer your question - Yes, it's very feasible to make one's own dies and one doesn't need very sophisticated equipment to do so either!



One additional note here:

My brother made some dies like the above but instead of 1/4-inch plate steel he used 1/8-inch steel with two 1/4-inch plates on the side like mine. Before assembling them he took a file and "knocked" the edges off just a little. This seems to work just fine and if he doesn't want any marks on the material being bent he just adds a piece of cardboard.

10-13-2008, 10:37 PM
Thanks guys Mike I really like your idea of laminating multiple pieces together thanks for the idea.

10-13-2008, 11:24 PM

From what I know “thin wall tube” like exhaust tubing and .095” to .150” take different types of benders

I have 1 of these


and yes you can get the accessory “Thin Wall” pinch rollers


It will do thin wall with the pinch rollers but it is still not the quality job a good "Mandril Bender" (which exhaust shops use) will provide you.

Although it is rather nice having "Push Button Power" wrap 2" x .150" wall tube around a 90 deg with only straining your index finger

take a look and see if there are any “Electrical Contractors” auctioning off their shops.

10-14-2008, 11:05 AM
Have a long term project going, for a 2 1/4" exhaust tubing bender loosely based on this design:


Am presently making the die which is one of those "throw away wheels" (temporary spares) that seem to be everywhere. A 120 deg. section looks to be about right, and it already has a 7 in. radius. Have cut it open and made it a little wider, that gives it three point contact on the tubing, which may not be enough. I suspect it will need some more support in the corners, but am not far enough along to try it out.

I am not looking for perfect bends, just something that does not squash the pipe.