Keep in mind that not every PCB contains all the layers listed â the need for different layer types depends on the specifics of your design. Single layer boards typically include: a mechanical layer, a keep out layer, a routing layer, an overlay layer, a solder mask layer and a solder paste layer.
An austenitic (300 series) stainless steel will outlast both aluminum and steel exposed to rain or salt spray. Steel without a protective coating will do poorly in both environments but if properly plated or painted, may last a long time. The aluminum alloys likely to be found in many consumer products may develop âlawn chair diseaseâ exposed to at least urban rain and condensation but possibly also in cleaner environments as well (up to you to test).
Most ferrous metals are magnetic, but aluminum is not. A simple test can be done with a refrigerator magnet to determine what type of metal your scrap is made of. If the magnet sticks to the scrap, it is probably a ferrous metal, but if the magnet does not stick, your scrap is most likely a nonferrous material.. Sparks. This is a test for the machinist type, but if you have a grinder you can run it on the edge of your scrap piece. If sparks are produced it will be steel and if there are no sparks it is make of aluminium. Experienced machinists can actually tell what type of material it is from the type of sparks produced.