Manufacturing
The way that silencers are manufactured is heavily influenced by the choice of materials
and the batch size. The most widely used material today is mild steel which has
been ‘aluminised’, meaning that it has been coated with a thin layer of aluminium
to help it resist corrosion. Since corrosion can occur on the inside or the outside
of an exhaust, the material used for a good quality product will be coated on both
sides. Aluminised mild steel can be welded but this destroys the protective coating
in the area of the weld, therefore it is preferable to make aluminised silencers
with mechanical rather than welded seams. However, mechanical seaming is only an
option for standard shapes and sizes and also requires the batch size to be large
enough to justify setting up the tooling. Silencers which are made in small volume
or which have an unusual shape tend to be welded and can be made from either mild
or stainless steels.
(Photo: Mechanical seam on aluminised mild steel silencer)