Metal CD Holders               

	I like this one. It looks like it is made of mild steel which has been forged into shape then welded together. Forging is the process of taking metal, heating it to a bright orange heat and shaping it using an anvil. In the old days welding was done by getting the metal close to its melting point and hammering pieces together until they joined. Now arc welding and oxy-acetylene welding is used. The coating is probably a kind of clear varnish which lets the texture and colour of the metal come through but at the same time stops it rusting (steel rusts you know but it is cheap and easily joined). Other methods of joining in schools could be brazing, silver soldering or riveting. You could even cast it. Click here to see methods of joining metals and casting.
This one is simple like the wooden one earlier. Its all don by taking a flat piece of metal and bending it into shape. Try making one out of cardboard. If you wanted the holder to accommodate more games or CD's you could just make it longer. If you made the thing out of plastic you could use a strip heater to shape it (look here ). I think this one is made of stainless steel which is rustproof and does not need coating. Some metals such as steel can be coated (called plating) with other metals to make it look better and stop it rusting. One example is chrome plating look here to see other finishes. . Plastic dip coating is another way that metal can be coated, look here
	Another all metal one. Study it carefully it looks like the wires that hold the CD's are all the same shape. They are like loads of U shapes fixed onto the legs. What is easy about that is that the U shapes can be mass produced and jigs can be used to bend the metal in exactly the same shape every time (that's what jigs are for you know repeating jobs which you need to be the same every time look here). Again the fish looks like chrome plating or paint. Look at those little balls on the ends of the legs. What are they for? to make it look better and fore safety (so you cant poke your eye on the ends if you were bending down and not concentrating. How do you think they might be fitted on, well either welding brazing or silver soldering (look here ) or you could put screw threads on the ends of the bars and screw them on, take a look