Usually, About the choice of materials, there are 3 types main materials for manufacture Metal shield: Nickel Silver (generally preferred), Tinplate and Stainless steel, and usually will not need do surface finish on them.
1) Nickel Silver and Tinplate can be soldered, but Stainless steel material can’t be soldered.
2) Nickel Silver can be oxidized, but not easy to rust. Tinplate is easy to oxidize and rust. Stainless steel can’t be oxidized and rusted.
3) Nickel Silver’s price is highest, Tinplate’s price is lowest.
4) Nickel silver and Tinplate are 2 types main material for manufacture 1-part Metal shield; And the main material for 2-part Metal shield: Shield Cover (Stainless steel or Nickel Silver) + Shield Frame (Tinplate or Nickel silver). But for 1-part Metal shield, our factory usually recommend Nickel Silver to our most of customers.