If you want to use metal shapes in your jewelry designs, you should consider cutting them yourself with the die cut method. A die is a mold like a cookie cutter that is used to punch through a sheet of material to create multiple pieces of the same exact shape. You will need a strong die that is made for cutting through sheet metal, because a die that can cut through card stock may not be strong enough.
Open the two blocks by turning the handle in the middle counterclockwise, just enough so that you can slide the piece of sheet metal between them. Insert the piece of sheet metal so that it is underneath the opening of the size of the shape that you want. Turn the handle in the middle clockwise to close the blocks and hold the sheet metal in place.
Place the corresponding die-punching tool into the hole for the shape you want. Gently tap the top of the die-punching tool with a standard hammer a few times. Keep tapping until you feel the punching tool go all the way through the piece of sheet metal. The shape that you punched out will fall through the other side of the hole.
Pull the die-punching tool all the way through the hole to remove it. Smooth the sides of the shape with an emery board to get rid of any sharp edges. Now you can punch a hole through the top and stamp letters or shapes into the metal shapes and wear them on necklaces.