I am in need of some small copper discs, 1/16" in diameter and 1/32"
thick, and I need about 4,000 of these. I am thinking of talking to
perforated metal sheet manufacturers to see if their scrap would become
my treasure, since I figured that they use die cutting to cut round
holes on sheet metal. Would this work or am I being naive ?

"Bo-Ming Tong" wrote in message
oups.com...
I am in need of some small copper discs, 1/16" in diameter and 1/32"
thick, and I need about 4,000 of these. I am thinking of talking to
perforated metal sheet manufacturers to see if their scrap would become
my treasure, since I figured that they use die cutting to cut round
holes on sheet metal. Would this work or am I being naive ?


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

Call Bokers, Inc 1-800-WASHERS
http://www.bokers.com/

They make custom washers from ALL sorts in all sorts of materials, sell
the washers, the holes, and the perf strips

Bo-Ming Tong wrote:
I am in need of some small copper discs, 1/16" in diameter and 1/32"
thick, and I need about 4,000 of these. I am thinking of talking to
perforated metal sheet manufacturers to see if their scrap would become
my treasure, since I figured that they use die cutting to cut round
holes on sheet metal. Would this work or am I being naive ?

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.


--
My experience and opinion, FWIW

Steve

On 25 Dec 2005 02:38:20 -0800, "Bo-Ming Tong"
wrote:

I am in need of some small copper discs, 1/16" in diameter and 1/32"
thick, and I need about 4,000 of these. I am thinking of talking to
perforated metal sheet manufacturers to see if their scrap would become
my treasure, since I figured that they use die cutting to cut round
holes on sheet metal. Would this work or am I being naive ?

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

"Steve" wrote in message
...
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.


--
My experience and opinion, FWIW

Steve