custom C-pillar construction, what is the radius of the bends in the corners?

Just won a M1123 on gov planet and am waiting for the paper chase to work itself out so in the meanwhile I'm doing a lot of learning.

So I do some fabrication and I'd like to make my own C pillar for this thing.

I found a quality source for aluminum and steel tubing and plan to use a tube steel bender to make my own C pillar.

Two questions:

1. Does anyone know what the internal or external radius is on the C-pillar curves?

2. What is the exact angle between the sides and the top?

Thank you for any insights related to custom C-pillar construction.

No offense, but you could probably buy a C pillar quicker and cheaper than it would be to make your own. Unless you have some exotic mod in mind.

nothing exotic. I like the challenges of doing fabrication, and if this works out could possibly productize. Materials cost is about $20 and these sell for around $400 looking around. Are the C pillars aluminum? If so there's no way they function as roll bars

cryptofile said:

nothing exotic. I like the challenges of doing fabrication, and if this works out could possibly productize. Materials cost is about $20 and these sell for around $400 looking around. Are the C pillars aluminum? If so there's no way they function as roll bars

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I bought a soft top kit and it came with the hardware (bows, cpillar, etc) The C pillar is aluminum (super light - about 10 pounds). Its in my garage because I didn't need it. $400 is ridiculous. I wouldn't pay more than half that (even with shipping)..... just looked on ebay. The prices for a c-pillar suggest to me that people are trying to recoup the cost of the soft top kit that it came in (because they didn't need a new c-pillar, like me).

cryptofile said:

nothing exotic. I like the challenges of doing fabrication, and if this works out could possibly productize. Materials cost is about $20 and these sell for around $400 looking around. Are the C pillars aluminum? If so there's no way they function as roll bars

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They are in fact aluminum and absolutely do NOT function as a roll bar. Mine holds my speakers and since it is hollow I was able to run the wires through it for a nice clean install, but I would much rather have the protection of a roll bar up there. Not that I do anything major with mine that I should need one, but you never know.

Slantback and GMV C Pillars are about 11ga 0.12" steel seamless tubing. Be advised there is a difference between a "pipe bender" and "tubing bender" so research first before buying at ChiComFreight.

For a soft top ?
or a hard top ? with or without turret support?

If soft top you should be able to find one for less then $400


Standard slant back C pillar tubes don't actually have any bends in them . They are however crushed or flattened in spots.
If your going to try and copy a OEM slant back C pillar tube your going to need to make a set of dies and one hell of a press.
Then some sheet metal to skin them with and a spoon for the center rear turret support. or multiple spoons .

I just found a GMV "C" Pillar for $2000+ Dang. https://www.hmmwvsupply.com/body-parts.html

From the looks of how these are built (angle iron, some plate, and pipe mostly) I can weld this up for about $150.

helpful thread on custom c pillar here: https://www.steelsoldiers.com/threads/hmmvw-roll-bars.179974/

Hey, don't know if you have already completed your c-pillar project. I am currently in the middle of my own and stopped in to see if there was any info on the angle that they are kicked forward. While I'm here, thought I could share some things I've picked up. Have been in touch with a fella out of North Carolina that manufactures the special forces c-pillars out of sch40 steel pipe. This is how I am constructing mine. It will combine with and additional arch that will come from the rear bumper. I am using a JD2 model 32 pipe and tubing bender. The die is a 2" sch 40 or 2.375 o.d. with a 5.5 inch centerline radius. This lines up perfectly with radius of the roof.

If anyone knows the angle the c-pillar leans forward, please post it. I am ready to weld now and will just go with what looks good and doesn't interfere with removing the welder if I can't find the correct angle soon.

*edit* I decided to match the angle of the welder. Its not as steep as original equipment but I like the parallel lines. Used a rear door to detemine what I thought might be the correct angle, it doesn't look good for this application. Good luck with your project.

Lothar said:

If anyone knows the angle the c-pillar leans forward, please post it. I am ready to weld now and will just go with what looks good and doesn't interfere with removing the welder if I can't find the correct angle soon.

*edit* I decided to match the angle of the welder. Its not as steep as original equipment but I like the parallel lines. Used a rear door to detemine what I thought might be the correct angle, it doesn't look good for this application. Good luck with your project.

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Did you ever figure out that angle I’m looking for it also.

I used a different angle that worked for my purposes. But I could get a measurement that matches the door angle for you. The only catch is, I won't be back in town until the end of the month, so I won't be able to until then.