Unlike carbon steel, Stainless Steel is corrosion resistant. It contains chromium which, when exposed to oxygen, creates an invisible protective film. Stainless steel types are classified into three different groups based on their ability to be hardened. Austenitic stainless steels, which can be hardened by cold working, meet a wide range of design criteria. They are essentially non-magnetic, although they may become slightly magnetic due to cold working. Martensitic stainless steels are straight-chromium types that can be hardened by heat treatment. They are magnetic. Ferritic stainless steels, Martensitic stainless steels, are also straight-chromium types and are magnetic. Ferric stainless steel, however, cannot be hardened by heat treating and are only moderately hardened by cold working.
Commonly Perforated Stainless Steel Types
304 (Austenitic)
One of the most widely used general-purpose stainless steels. It possesses an excellent combination of strength, corrosion resistance and fabricates well. To reduce carbide precipitation when welding, use 304L for its lower-carbon content.
316 (Austenitic)
Superior corrosion resistance compared to other 300 series alloys when used in used harsh corrosive environments (ex. sea water, chemicals, etc.). To reduce carbide precipitation when welding, use 316L for its lower-carbon content.
321 (Austenitic)
Titanium stabilized stainless steel to prevent inter-granular formation of chromium carbide. It exhibits strength characteristics superior to those of 304 stainless, thus making it best suited for parts which cannot be subsequently annealed.
410 (Martensitic)
The lowest alloy content of the three general-purpose types. It is a heat-treatable chromium type used for highly stressed parts needing the combination of strength and corrosion resistance.
409 (Ferritic)
The lowest chromium content of the stainless steels, 409 combines good elevated temperature corrosion resistance with medium strength, good formability, and overall cost.
430 (Ferritic)
A general-purpose non-heat-treatable chromium type used for highly polished trim applications in mild atmospheres. Its strengths are in ductility, formability, good corrosion and oxidation resistance, thermal conductivity and finish quality.
NOTE: If a stainless steel type is not specified, Diamond Manufacturing Company will use 304, which is the most commonly perforated stainless steel for pricing and production.
