Extrusion Hole Size

[rscholl23]

Hello All, New tooling designer here...I was wondering if anyone would be able to help me out here. I am curious as to how you figure out the pierce hole size before the extrusion for the inner wall, I am designing a progressive die to make this part and the first station will be piercing the pilot holes and the hole before the extrusion. Some key reference points: material is .018" 304 SS, extrusion ht is .250" and the ID of the inner wall is 1.546"

Thanks!

 

[rscholl23]

I think i figured it out without a formula (let me know if I am no the right track)...I calculated the volume of the part without the pierced hole (blank size)and subtracted that volume with the finished parts volume. WHat I was left with should in turn be the volume of the pierced hole, correct?

 

[mfgenggear]

I marked this thread, since I have been out loop for sheet metal for a while,
I have forgot lots, so but my instincts say's no incorrect, I am busy now,
I will have to jump in later.

 

[FACS]

Piercing does not remove material.
Then you extrude the remaining material.
So you never remove material?

Then the volume is always the same because you never removed any material.

So I'm confused

 

[mfgenggear]

here is what I could find in a limited time, I suggest purchase a blank and pierce and forming handbook, it has all the equations,
I have one but it is a hard copy, so the internet it is

https://slideplayer.com/slide/6386486/

 

[mfgenggear]

one more

 

[mfgenggear]

let me know if this worked