two stage punch tool project

[10] Like what you see?
Click here to donate to this forum and upgrade your account!


Mar 1, 2017
Using the example of soda can forming, I need a tool that can put a >0.050" wall on a 1/2" diameter aluminum disk. I was hoping a spring loaded punch could drive aluminum into a two stage former to accomplish this.

How doable is a single throw, two stage punch and former to accomplish the goal above? The following describes the function:
1. Aluminum sheet (0.010") is fed over a 1/2" round cutting former.
2. A punch head (0.400") drives the sheet through the first stage former cylinder to create the 0.500" disk.
3. The cut disk lands (slightly concave?) on the second stage former cylinder (0.410").
4. The punch pushes the disk up into the second stage which forms the wall and irons the thickness -0.005.

The questions around this process are:
1. Is a 0.400" punch head sufficiently large enough to get a workable 0.500" disk?
2. What is the optimum shape of the second stage land (flat or contoured to match any disk deformity)?
3. If the punch stretches the aluminum slightly before the cut, will 0.120" be enough space between stages?
4. Will the walls tear with 50% ironing, what is the likely maximum ironing at room temperature?
5. How far does the part need to travel in the exit former to hold its newly formed walls?
6. How much taller will the walls get from the ironing (how much loss)?


H-M Supporter - Gold Member
H-M Supporter - Gold Member ($25)
Apr 27, 2017
I think you might have more luck giving us a application, an aloy number, and if possible a part drawing.


Active User
May 14, 2013
It sounds to me like you are building a gas check maker? Send me a PM with your email and I can send you info that I have . The tool you desire is not overly difficult to do just time consuming if you are trying to keep close tolerances.
[5] [7]