Bolting

• You can bolt together any kind of metal that you can drill a hole through. For example, you could bolt a metal "For sale" sign onto a cylindrical metal post. One way of achieving this would be to mark the vertical center line of the sign, then drill two holes on the line about one inch from each edge. Place the sign against the post and make marks through the screw holes. Remove the sign and drill through the post at the two points. Place the sign back in position, slip the bolts through the holes and through the post and fix nuts on the back of them.
  
  

Soldering

• According to Dr. Dmitri Kopeliovich, Ph.D., you solder two pieces of metal together by employing a third metal called solder. You don't need especially high temperatures to join metals in this way. You simply have to have a way of melting the solder. A soldering iron is the usual tool of choice. The solder melts then flows between the two pieces of metal, solidifying when cool. Fusing of the two metals joined does not occur.
  
  

Arc Welding

• Arc welding uses a power supply to melt the metals at the welding point with an electric arc. According to MIG Welding, arc welding is particularly appropriate if you wish to join thick metal together. To start the arc, simply touch the electrode for a moment against your work. This has the effect of completing the electrical circuit and establishing the arc. Move the arc along the joint area with a steady motion, traveling at moderate speed.
  
  

Other

• Other ways to join metal include forge welding and gas welding. In forge welding, you heat up two pieces of metal to the correct temperature then hammer them together until they fuse. In gas welding, you use a welding torch. This heats up the areas of the two metals to be joined to such an extent that a joint pool of molten metal is created. You can additionally add a filler material to the pool. When the pool sets, the metals are joined.