If your like me and make scrap metal sculpture then it can sometimes be hard to identify what metal the scrap is made of. In this instructable I will show you how too identify some of the more common metals. NOTE: These are not all the metals there are, there are thousands and I couldn't possibly tell about all of them. Also if you bend tin it will make a light "snapping" sound.
Step 1: Ferrous or Nonferrous?
Ferrous means that the metal has iron content which in most cases makes it magnetic and nonferrous means it doesn't have iron in it. An example of a ferrous metal is mild steel, also known as low carbon steel. An example of a nonferrous metal is copper or aluminum. Its always a good idea to bring a magnet to the scrap yard.
Step 2: Aluminum
Aluminum is a shiny grey metal and has a clear oxide that forms on contact with air. This may not be the best thing for identifying it, but aluminums melting point is 658° C (1217°F). Also aluminum is non sparking. Aluminums density is 2.70 g/cm3, this is a good way to identify it because you can find the density of a material by density = mass ÷ volume. As i said earlier, aluminum is nonferrous.
Step 3: Bronze
Most bronze is an alloy of copper and tin, but architectural bronze actually has a small amount of lead in it. Bronze has a dark coppery color and gets a green oxide over a period of time. bronze's melting point is 850-1000°C (1562-1832°F) depending on how much of each metal is in it. Bronze is nonferrous. Because bronze is an alloy densities vary. Bronze vibrates like a bell when hit.
Step 4: Brass
Brass is another copper alloy but it has zinc instead of tin. Brass has a yellow gold color. Brass' melting point is 900-940°C (1652-1724°F) depending on how much of each metal they used. Brass is nonferrous. Because brass is an alloy its density varies. If hit brass vibrates like a bell, this can be used to determine if something is brass instead of gold.