As custom metal parts manufacturer, the material scopes we used is listed for your reference as follows:

Casting / foundry (steel, cast iron, stainless steel and aluminum etc.)
Steel (Q235, Q345, St355J2, St52-3, mild steel and 20CrNiMo etc.)
Stainless steel (304,316 and 430 etc.)
Aluminum (A356, 6061T651, 6063, 5052 and 2124 etc.)
Cupper
Brass

We also provide following surface coating/treatment by outsourcing:

Zinc plate/cold galvanize (Cr3+ RoHS free or Cr 6+).
Hot galvanize
Zinc spraying coating
Aluminum spraying coating
Chrome coating
Anodize / anodic oxidation (max. available length of the aluminum profiles are 30m)
Alodine coating
Brown finish
Teflon coating
Rubber coating (NR, NBR and EPDM etc.)
Paint
Powder coating
Passivation
Case hardening
Soft nitridizing