How sheet metal is made November 05, 2007 1:09 AM
1.This is a steel ingot. It is used as a mould (I call it an ingot mould). It comes apart for removing the metal, so it is clamped together.
2. This is called a crusible. It is a ceramic dish that can withstand the heat of the torch. The piece wrapped around it is steel, and it holds the long handle on.
3.The crusible holds the scraps of metal.
4. Here you see the torch melting the metal. To do this, it needs a lot of heat. The melting temperature of sterling silver is 1640 degrees F.
5. You must wait until all the metal has melted before you can pour. Very carefully, hold the crusible as close to the ingot as possible, and keep the flame on the metal as you are pouring. If you don't, it won't all harden together, and you will end up with more than one chunk of metal.
6. Once the metal has cooled, you can remove the clamp, and release the slab of metal. This slab is also called an ingot. You must then pickle your metal ingot.
(Pickling is a chemical bath that helps clean the metal).
7. This is a rolling mill. It is a lot like a pasta machine, except it's meant to roll out metal, not pasta dough.
8. The metal ingot gets passed through the rollers.
Going through the rollers will work-harden the metal, so it will need to be frequently annealed* (see below).
With each pass, you make an adjustment to make the rollers a tiny bit tighter. This will (eventually) make the metal longer and thinner. This can take several hours.
Annealing metal is the process of heating it with a torch to make it a
bit softer and easier to work with. Each time it is annealed, it must
be put in the pickle again to re-clean it.
This is why it takes so long to roll metal.
Once it is the desired thickness, it is ready to be used.
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