Next challenge: What tool to use?

[moribundman]

I want to cut a disc with a hole cleanly out of a 1 mm thin sheet of aluminum. How do I go about it?

This piece has been cut out of styrene with a circle cutter.

 

[Pablo]

I actually have somewhat of a similar dilemma. A thin (~1mm) head gasket made from Al for a single cylinder engine. One nice hole for the bore, four for the studs. Need to make enough gaskets to make it commercially viable. IMHO punching will be best - but tool design/making will be expensive. Don't want to draw, or tear, or bend the material and other hazards of punching such a ductile sheet. I have a press, so it will be better than a hammer smacking event……I have yet to experiment.

 

[moribundman]

In the worst case scenario I will sandwich the sheet metal between wood and cut out the shape with a scroll saw, then file and sand by hand.

 

[Papa Bear]

If you can hold it real steady like in your photo, I could blast a hole in it with a 105 Howitzer.

 

[moribundman]

I'll let you hold it for me.

 

[Pablo]

Heck with that, look at the perfectness of mori's thumbnail!

 

[moribundman]

That's a prop hand.

 

[NJC]

I'd use a punch.

 

[moribundman]

I'll get back to you after setting up a fully equipped machine shop!

 

[Papa Bear]

Maybe Mori's day job is as a hand model.

 

[moribundman]

Isn't that your job, George?

 

[NJC]

I'd use a [hand] punch [if I had no machine tools].

 

[moribundman]

All the hand punches that I know can punch only small holes, sort of like a paper hole punch. What kind of hand punch do you have in mind?

 

[NJC]

Apparently they call them arch punches.

 

[moribundman]

Interesting. I've never before seen that type punch. What are the odds I can find two in the right size? Almost zero, I bet.

 

[Pablo]

Yeah no common punch for my bore size.

 

[NJC]

which sizes? BTW, I have 2 of these punches in 25.4mm and 12mm diameter so I tried to punch a ring out of a .9mm sheet of alum. Not ideal ...

 

[NJC]

deleted.

 

[NJC]

Originally Posted By: Pablo
IMHO punching will be best - but tool design/making will be expensive.

Laser cut?

 

[Pablo]

Bore is 48 mm or something (at work, can't remember). It will take a special tool....and backing plate...