Hi Trish,
I'm looking for bronze sheet, too. I haven't purchased any yet,
but I did find some heRe: http://www.hagstoz.com
Not picking on you or Hagstoz but I hate it when metal suppliers are
not specific about what alloy they are selling. So it is bronze but
which alloy is it? Silicon Bronze? Aluminum Bronze? Phosphor Bronze?
Commercial Bronze? Each has very different mechanical properties.
All the above alloys with the exception of commercial bronze are
springy and tough and hard to do much with in the way of fold forming
or really any hand forming.
Some rough definitions for copper alloys:
Coppers and High Copper alloys are greater than 98% and 95% copper
respectively. Brasses are copper alloys that have zinc as the largest
percentage alloying element. Unless it contains nickel then it is a
Nickel Silver if the copper content is less than 75% or a Copper
Nickel if it is greater than 75% copper. Everything else is a Bronze,
which can have aluminum, silver,tin, titanium, or zinc as the major
alloying element and most have several elements in the mix.
The only wrought bronze alloys that have significant amounts of tin
in them and are sometimes referred to as tin bonze are the phosphor
bronze alloys.
From copper.org
Phosphor Bronzes, or tin bronzes, are alloys containing
copper, tin and phosphorous. The phosphor bronzes contain
between 0.5 and 11% tin and 0.01 to 0.35 % phosphorous. The
addition of tin increases the corrosion resistance and strength
of the alloy. The phosphorous increases the wear resistance and
stiffness of the alloy. The phosphor bronzes have superb spring
qualities, high fatigue resistance,excellent formability and
solderability, and high corrosion resistance.
The excellent formability they are referring to is in press or other
mechanical forming work as the characteristics of stiffness and
superb spring qualities make it difficult to hand form. Just ask
someone who has tried to raise a vessel from phosphor bronze, it is
tough stuff.
So unless your project needs to be strong and stiff use commercial
bronze (Cu90, Zn10) which is nice to work but is a brass.
The fuzziness of the terms brass and bronze are nothing new, the
word bronze is derived from the ancient Persian word for brass
James Binnion
@James_Binnion
James Binnion Metal Arts
360-756-6550