As with most production, making wire starts with the melting
of the gold, silver or platinum. Here
the gold is in the crucible in the induction furnace and has mostly
melted. However, if you look closely,
you can see on the top of the melt some scrap pieces from previous production
that haven’t quite completely melted.
Melts for production may contain left over gold from previous
manufacture, new pure (.9999+) gold with other metals (alloys) or a combination
of both.
The gold is completely melted and being stirred to ensure
homogeneity.
The gold is being
poured into an upright rod form.
The rod after it has been removed from the form and cleaned. The large button shape at one end is where the melt filled the very top of the form that is flared to allow ease in pouring.
The rod after the flared top has been cut off. This must be done because this large end
would never pass through the mill in the rolling process.
The first step is to
roll the rod through the square wire rolling mill where it takes on a square
shape while lengthening considerably.
The rolling is continued until the square wire is just
sufficiently larger than the round wire
desired so that when pulled through the round dies the final diameter desired
will be achieved.
The end of the wire is crimped thus allowing it to enter the
round wire die with ease.
The wire being inserted into the round wire die.
Here the wire is seen emerging from the other side of the
die, ready for drawing.
The die is mounted in the draw bench for the initial drawing.
The wire is drawn far enough on the draw bench to allow it
to be mounted on the automated drawing machine.
Here the wire is being drawn through the die and wound.
From a different angle the wire can be seen being coiled as
it is being drawn down.
As the wire is drawn thinner and thinner, it becomes harder and harder. Eventually it needs to be softened to allow further drawing. To achieve this, it is heated to a specified (depending
on what type of metal it is) high temperature for a specified time, a process that is known as annealing. It can then be drawn down further. Depending on how thin the final wire needs to be, it may require annealing several times.
Several examples of finished karate gold , silver and platinum round wire.