Pipe bender - does it work and will it bend 40mm steel rod

[Calum Nicoll]

I'm wanting to bend a 6ft piece of mild steel, and it's rather awkward to lug around - so wondered if anyone knows if pipe bender working/ is capable of bending 40mm stuff. It doesn't need to be a tight bend - radius of 1m would be just grand.

Cheers
Calum

[Spike]

The pipe bender is designed (I assume) to bend 25mm hollow steel pipe.

How much more effort do you think will be needed to bend a solid steel
rod of 40mm diameter.

At minimum you will need a hydraulic press to make an impact on your
rod, you will likely need a lot of heat and a roller.

Spike

[deanforbes]

heat it up and pull it around a cylinder is what I would do 

[Calum Nicoll]

I believe the bender is hydraulic though? https://wiki.london.hackspace.org.uk/view/Clarke_Strong-Arm_12_ton_pipe_bender

Saw this vid of folks bending similar steel with what I believe is an 8 ton press - https://www.youtube.com/watch?v=bCha8RiH7fQ

Heating is probably a last resort - the curves don't need to be tight and it just needs a couple of rough curves/doesn't need to be a perfect round shape.

[Ken Boak]

The clue comes from the name "pipe bender" - it's for bending pipe, not solid bar.

If you are making something out of 40mm bar - you need to ask yourself why are you using such heavy material?

Even the rebar that is used to reinforce concrete piles -  seldom exceeds 25mm in diameter, and this represents about the limit that can be formed using simple techniques.

I had to bend some 12mm rebar for a job, and resorted to heating to red-heat with an oxy-acetelyne torch - and bending in a large bench vice. Even this was hard work.

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[Toby Catlin]

So the CHV12 bender says it can do 2 inch pipe which is 53mm, but doesn't mention wall thickness. So I would say 40mm rod might be possible but deffo pushing it limits to the max. 

Dean's suggestion of heat and some kind of form will work as long as you can get enough heat into it. Also a long lever, like a bit of scaffold pole may well give you the grunt you need.

t

[Ken Boak]

You might be able to ascetain the practical limitations of this machine here

http://www.mig-welding.co.uk/forum/threads/clarke-chv12-12-ton-pipe-bender.3085/

Sounds like 50mm diameter scaffold tube (5mm wall) is about its limit.

Why would you need to bend up anything in 40mm solid bar -  bar is for turning, not for bending.  

You might also wish to look at the mass in kg per metre length  (9.86kg/m for 40mm) and ask why are you spending a fortune on unnecessary metal.

http://www.rosmetalloprokat.com/index.php?option=com_content&view=article&id=58&Itemid=56

Not unsurprisingly, I was schooled in the 1970's when they actually taught us this stuff.

[Paddy Duncan]

It does in the manual....
The thickest walled 2" pipe it mentions has a cross sectional area of approx 800mm^2
40mm bar is approx 1250.
But, at its widest setting I reckon it would do it without issue

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[Ken Boak]

Yes but a nominal 50mm scaffold tube with a 5mm wall thickness is 800mm2.

Pi x D = 157mm

800mm2/157 = 5.09mm.

You are asking this poor 12 tonne bender to bend a 40mm tube with effectively a 20mm wall thickness - but solid - so there's nowhere for the metal to go.

Here's a bender for 40mm bar and it weighs 481 kg and can give a force of 500N per mm2. so your 1250mm2 will need  (1250x500N)  - which is about 625,000N or about 62.5 tonnes. Sounds like about 5 times the capacity of the Clarke pipe bender.

https://www.specialisedforce.com.au/downloads/products/Bend3r-45.pdf

This might also be useful - force to bend a 25mm bar

http://weldingweb.com/showthread.php?28778-how-much-force-to-bend-1x1-quot-solid-steel

And this - to bend a 2500mm length of 10mm sheet

https://engineering.stackexchange.com/questions/3326/how-can-i-calculate-the-force-required-to-bend-a-10-mm-thick-plate-in-a-rolling

[Jim Hayes]

Cut Vs in it, bend at those and weld it up? Depends on what you want it for I guess.
You'd also have to allow for the weld contracting, pulling a tighter radius that you'd bent into it.

[deanforbes]

I would not use this type of tool up to its rated capacity never mind over it 

heating and bending in my view is likely to be quicker and easier 

On Saturday, 12 August 2017 01:16:02 UTC+1, Calum Nicoll wrote: