We should put the bottom piece in position to check the locations where we should drill the holes. The
holes should be the same size as the outside diameter of the sheet metal screws used. Now place the
bottom piece in position again and locate the drilled holes on the side flanges of the bottom piece.
When located, remove the bottom piece and drill the holes the root diameter of the screw where you
marked them. Assemble the bottom piece to the case using sheet metal screws.
Sheet metal screws are self-tapping so to fasten two pieces of light gauge metal. The outer piece of
metal is drilled to the outside diameter of the sheet metal screw and the inner piece drilled to the root
diameter of the screw. By drilling the holes this way the sheet metal screw will bring the two pieces
together and hold them tightly.