Metals – Types, Grades

PLAIN METALS

STAINLESS STEEL ALLOY 304

This is the metal of choice for most architectural and any decorative surfaces. Ideal for fabrication. It is highly resistant to corrosion and therefore suitable for outdoor applications. No protective coating is required.

STAINLESS STEEL ALLOY 316

It is rarely used except when its particularly strong resistance to corrosion becomes a factor: chemical environments or similar exposures. It does not require any protective coatings.

STAINLESS STEEL ALLOY 430

Not usable for architectural or other quality installations, this alloy contains a fair amount of iron and will therefore oxidize. It is commonly used for lower grade fabrication.

BRASS ALLOYS 464 – 260 – 280

This yellow metal is a copper alloy and is available in many different alloys, having different trade names. Alloy 464 is called Naval Brass, Alloy 260 is called Cartridge Brass and Alloy 280 is called Muntz. All 3 are very close in color. Naval Brass in quality grades is widely available. Muntz, best known by architects, has become increasingly scarce in recent years. It is highly recommended to specify Naval or Cartridge Brass for decorative applications. Any brass will need to be clear lacquer coated to prevent and retard tarnishing. It is not recommended to specify brass for outdoor applications, especially not in hot and humid tropical or marine environments, or in non-air-conditioned buildings in such climates.

BRASS ALLOY 220 (COMMERCIAL BRONZE)

Because of its trade name “Commercial Bronze,” this alloy is commonly referred to as Bronze (real Bronze does not exist in sheet form). Its reddish color is highly attractive and can be matched with hardware in real bronze. Again, this alloy needs to be clear lacquer coated and all other recommendations for Brass will apply.

COPPER ALLOY 110

Plain copper sheets in their reddish color are very beautiful. But many of the more complex decorative finishes can only be applied with great risk or subsequent, residual tarnishing. Best uses for copper are full sheet oxidation finishes and textures on metal laminates. Again, copper needs to be clear lacquer coated and all other recommendations such as for Brass apply also for Copper.

ALUMINUM

This material is the most common metal on earth and it exists in many different alloys, grades of hardness and quality. Most are suitable for the various decorative finishes. Since Aluminum does oxidize, albeit very slowly, a protective coating is necessary. The coating for outdoor applications is anodized, whereas clear lacquer coatings are sufficient for indoor applications. Aluminum can also be dyed successfully with organic dyes or coated with transparent colored coatings. Aluminum’s main features are: light weight and low cost. Ease of cutting light gauge material by conventional means; give it a much wider market for decorative applications than Stainless Steel.

COLD ROLLED STEEL

This is the professional name for ordinary steel sheets; the most widely used sheet metal in fabrication and construction. Because it is basically an iron alloy, it needs to be particularly well protected against rust. This metal is only suitable as a base metal for decorative applications in paint and vinyl coatings, for example.

METAL LAMINATES

STAINLESS STEEL – COPPER – ALUMINUM – BRASS

All of these metals are widely used as metal laminates. The most common metal is aluminum, either clear coated or anodized. A metal laminate is a sandwich of a thin metal foil bonded by glue + pressure to a substrate of phenolic resin or similar. Or 2 thin sheets of plain aluminum are sandwiched over a resin core. ALMOST ANY OF THE DECORATED FINISHES DISCUSSED HERE CAN BE PRODUCED ON THESE LAMINATES AS WELL AS ON PLAIN METAL. While metal laminates are lighter, generally less expensive and easier to cut to size than plain metals, the choice between both will depend on physical characteristics. All major HPL distributors distribute extensive documentation on metal laminate specs and recommendations how to handle and fabricate.