vdr20 said:
What are your thoughts on using 430 stainless steel? If it’s magnetic, should the shielding be okay? Or are there other factors at hand?
430 stainless steel has about half the magnetic permeability and 1/4th the conductivity of mild steel, so it's not as good as a magnetic shield. Is it good enough? Only you can answer after you build and measure it...
Why are you so concerned with corrosion?
Painting over SS is difficult. Primers work by penetrating the atomic boundary of materials; SS is stainless because its boundary is closed.
I've had SS chassis made for some builds. I left them unfinished because the painters told me to. They'd rather see an unpainted stainless chassis than one where the paint (even epoxy powder) would peel. Leaving them unpainted was also a way to compensate the increased cost.
OTOH I've had most of my chassis made from zinc-plated steel. The thickness of Zn is about 1/5th that of galvanized steel.
It's the standard in electronics packaging.
It can be chromated after, which will provide protection of the edges, which are left unprotected after punching/machining.
Optional chromate will also provide increased paint bonding, which is already very good without it.
SS is also mode difficult to work with.