how to punch thin stock

Hi. I am having a bit of a problem punching thin stock. Everything goes according to plan until the end. I hit the punch from one side, see the "rosette" on the other side, then hit from the other side. The second hit does not seem to do anything. It seems that the problem is that there is not enough displacement on thin metal to cause the round wafer to shear off. It still is stuck, and there is now a "rosette" on the other side. If I put the piece over the pritchel hole and strike, the wafer comes out, but there is a problem with deformation. Is this just the way things work?

Thanks, Eric

Reply to
Eric Chang
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If I'm not mistaken, you should hit it from one side and when you see the impression on the other side, flip it over the pritchel hole and hit it through.

There will be some slight deformation, but it shouldn't be too bad. If it is, punch a smaller hole, use a drift to expand the hole to the desired size, and file down any sharp edges that may remain.


Reply to
Rick Barter

How thin? What metal? Hot or cold? What size hole?

Mild steel, 16ga or less, punch it cold against the end-grain of wood or a lead block. Easy. Be sure the punch has a sharp edge.

-- Carl West

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Reply to
Carl West

Eric, Just drill it! You could also try stacking several pieces together and hot punching through them all at once. Or drill an undersized pilot first then use a punch to size the hole.

Glen G.

Reply to
Glen G.

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