UK Penny Hat

Using a 10mm bearing (9.6mm on the calipers!) in the 14mm hole of a dapping block and the attached alignment tool (https://www.amazon.co.uk/dp/B08MLD8J8) or just make your own alignment tool, this stretches the penny into a small hat.

Frankly it's an easy design to knockup on Tinkercad for any size bearing so you can customise your hat a bit if you want.

Perfectly legal like the coin smushing machines as it's not destroying the penny or melting it down.

Make sure you use pre-1992.  Anneal the coin by heating it up until cherry red.  Clean the coin with an old toothbush or sandpaper if you want before pressing.  Obviously let it cool first.

Put the coin into the plastic ring with the bearing on top and use in a press (we have a 12tn press at the hackspace we use) & it takes very little effort.  We have tried in 1tn arbor presses without luck.

The coin exits more bowed than you'd think, but using the side of a sledge hammer as a mini anvil, you can put a dink in the top with something long like a metal/concrete chisel and it'll flatten the brim out.

You could feasibly drill a hole in it and use it on a keychain, or as a hat for a hamster (don't let your hamster or other house rodent eat it pls.  It won't be good for them)

Enjoy.