Making small copper discs ?

It should be possible to punch such discs from sheet copper, but the edge on the disc may not be clean and sharp. A lot depends on how sharp the punch and die are, and how much clearance is provided when they are made. If the disc must have sharp corners, you may have to machine them to achieve your goal.

Harold

Kinda OT, but this reminds me of a boat building experience (past life).

I was building a traditional out-rigger dugout canoe while living in the Philippines. The sides of the dugout hull were to be extended an additional

18" with 1/4 ply. The joint along the hull was traditionally copper rivets with copper backing washer.

I could get copper nails to cut off for the rivets, but couldn't find the washers. My boat building mentor handed me a local centavo (same as a penny). Suggested I go to the bake and get a roll of 100. He also reminded me not to tell them what I was going to use them for (illegal to deface currency). Dilled holes in the center of each, annealed them with a propane torch and had washer, cheaper than if I had to purchase them.

We make parts from 6-4 titanium very much like there by photochemical milling. Registering the masks on both sides of the metal sheet, once mastered, allows etching from both sides. Usually a tiny breakout tab is left so they do not all fall to the bottom of the etch tank. They are then manually plucked out. Once the artwork is made, you could easily make millions of them. Copper etches very easily with ferric chloride, sodium persulfate, etc. and does not involve the nasty stuff used for Ti. You end up with a tiny ridge at the halfway point of the thickness, but well-resolved edges on the surfaces.

My Grandfather did that in the 40's or 50's when he need copper washers for his boatbuilding shop. Pennies were cheaper than copper washers. Karl