MACHINING
All metal sections can be cut, so machining generally refers to processes beyond: drilling; milling; turning; pressing; rolling; folding.
WELDING
3 common types:
Arc (refers to its powerful electric arc): suited to larger stock – 2.5mm upward – of all steels. Not suitable for brass, aluminium and lower melting point metals. The most aggressive form of welding. Has good penetration (pushes into the stock). Generally the machines are more portable. Is limited by its aggression. There is a knack to the use of it, but once mastered will provide basic welding applications.
MIG (Metal Inert gas): best balance – covers all common steel profiles. Can be used on larger aluminium sections. Has a good range from small to larger sections. If the welder is set up right then the welding will easily yield results. Does require a gas bottle and so is less portable.
TIG (Tungsten Inert Gas): finer work – can do slighter sections of aluminium if ACDC. Not beneficial on larger stock or big productions. Requires gas bottle so less portable. Takes time to master the process.
BRAZING
A further metal-joining process using an oxyacetylene torch and a filler rod. Principles are similar to soldering, but temperatures and melting points are much higher. Not as strong as welding: acts more like a glue which bridges the surfaces, rather than fusing them together; uses a torch rather than a current. Brazing allows much more control and produces a cleaner finish. It also allows you to join different types of metals to each other and can even be used with non-metals (metalized ceramic).