Die angle for bending attachment

Hi guys,

I started to wade through the information online about springback and K factors but figured I'm going to get an easy answer here I hope you don't mind me being lazy.

I'm going to build a simple sheet bending unit for my press. Consisting of a V die, pillars either end, and springs around them holding a punch above it, maybe 400 long.

What angle should the die and punch be for 90 degree bends in 1-10mm steel/aluminium? Lets say more realistically 1-5mm steel and aluminium - though one day it'll get used for something bigger than it should be no doubt. I realise this is broad but for a home machine shop doing the sorts of stuff we do.

Not much of what is available online is actually specified. Am I better off going to 88 degrees and being careful with the lighter stuff, or...?

Thanks as always!

Lazy means someone else has to do the work.

If you are building a 400 inch press brake that is over 33 feet long, I commend you on your enthusiasim for buildinfg such a capable machine. I would suggest to focus on the tonage and stiffness needed and just buy the dies.
Nobody local to me has bigger than a 12 foot brake, send it out for 20 feet or more....
Most all dies are 88º unless you build your machine strong enough to do do coining, then you can use 90º a die to get a 90º bend.

NZ here fellers lol I was talking mm.

Talking about something like this
P450 - PBA-45 Pressbrake Attachment - Suits Hydraulic Presses | Machineryhouse

I prefer 85 degree dies because I can use die film to prevent marking and avoid the tonnage increase that tends to happen as you approach the die angle.

88 is fine if you aren't worried about die film, but being able to go a few degrees over 90 is pretty handy too.

you realize the bend angle is not adjusted with the die angle, right? springback will be different depending on what your bending. there is a 3-point contact, assuming you will be doing "air bending" (least amount of force).

also you wont be bending 1-10mm with the same die. what was it again, 8 x thickness?

JoshNZ said:

NZ here fellers lol I was talking mm.

Talking about something like this
P450 - PBA-45 Pressbrake Attachment - Suits Hydraulic Presses | Machineryhouse

Click to expand...

You need our help to copy/steal that "design" ???

Get a job, and BUY the damn thing.

dian said:

you realize the bend angle is not adjusted with the die angle, right? springback will be different depending on what your bending. there is a 3-point contact, assuming you will be doing "air bending" (least amount of force).

also you wont be bending 1-10mm with the same die. what was it again, 8 x thickness?

Click to expand...

8 times is the sweet spot but 4-16 works fine.

80 mm die opening for 10mm.

a 35mm die is good for 2-6.5mm steel and aluminum. 4mm punch tip minimum for 6.35mm aluminum, ideally same as material thickness.