Thread: folder ratings question

Hi all was looking at a 1200 mm folder rated at 1.6 mm mild steel, i take it they will bend this thickness at that width but when asking the salesman could it do the same width in 2.5 ali checker plate he didnt know ,ali being easier to bend is this possible or am i asking to much of the machine cheers Greg

Rule of thumb is double the steel thickness for Al and half it for SS, so you could but you also need to look at whether the 2.5mm checker plate will actually physically fit. Remember too that unless you are looking at an industrial unit, the capacities are normally optimistic. If you planned on doing folds like that regularly I would suggest a bigger unit (unless it is an old school folder that is solid as a brick ...)

Michael

Thats a good question. Not sure how easy it can be worked out, whethers its just a matter of comparing Youngs modulas and then scaling up to allow the extra thickness in material. My basic materials science knowledge tells me it would be more complex than that!

It also depends on what bend radius you wokuld be happy with and how much deflection yoh would be happy with in the leaf and other structural parts of the folder that would give rise to fold radius variations along the length.

Simon

Provided there is sufficient adjustment to move the fingers back and leaf down to accommodate the extra thickness, you should be in the ballpark. As others have said though, capacities of the chinese benders are optomistic at best.
My guess is you should be okay as you will not be using it in an industrial setting, but a look at some of the 2.5mm capacity units wouldn't go astray.

Originally Posted by simonl

Not sure how easy it can be worked out, whether it's just a matter of comparing Youngs modulus and then scaling up to allow the extra thickness in material.

I was thinking that too but having worked through the equations, it's in proportion to thickness of material^2 and yield strength.
In the case of Aluminum, the multiplier is 1.8 in reality (2 is close enough). This assumes normal Al, not the high strength stuff.

Stainless is a problem because it work hardens - so while you could assume that it has similar properties to steel as soon as you start bending it the work hardening kicks in and raises the yield. Copper and brass would probably cause similar issues.

Michael