Galvalume steel is carbon steel coated with an aluminum zinc‐alloy. The typical composition of the coating is 55% aluminum and 45% zinc. The coating is applied to the base metal in a continuous hot dip coating method. The product is described in ASTM‐792, coating classes of AZ‐50, AZ‐55 and AZ‐60. These classes equate to an average minimum coating thickness of .50, .55 and .60 ounces per square foot. Galvalume is a product of choice for most agricultural, commercial, industrial and rural applications. Under typical corrosive conditions, the coating generally will last much longer then a Galvanized coating of comparable thickness. Galvalume will maintain its bright appearance and reflectivity in long‐term service at temperatures up to 600 degrees Fahrenheit. The aluminum‐zinc alloy coating provides excellent atmospheric corrosion resistance in a wide range of environments under many diverse conditions. The alloy coating of aluminum and zinc gives a combination of long‐term corrosion resistanceand galvanic protection at scratches and cut edges. The coating is available as regular spangle or extra smooth suface. Galvalume sheet can be formed about as readily as continuously annealed galvanized sheet. Lock forming and roll forming are readily accomplished. It can be joined by various methods including riveting, soldering, welding and spot welding. Spot welding electrodes should be redressed as required to maintain nugget size. Galvalume sheet can be arc welded with the shielded metal‐arc and gas metal‐arc processes. The lower zinc content of the coating of Galvalume sheet results in considerably less fuming during arc welding.
Another product in the Galvalume family is Acrylume. Acrylume is Galvalume steel with an acrylic coating on top. The acrylic coating provides protection from fingerprints and other oils during the handling, fabrication and installation of the metal. Acrylume – because of the acrylic coating – should not be painted; it should be left bare.
Mechanical Properties
- Yield Strength: 38 ‐ 53 ksi
- Tensile Strength: 50 ‐ 65 ksi
- Elongation: 20 ‐ 36%
- Hardness: 50 ‐ 65 RB
ASTM Specifications
ASTM Designation A792 / 792M outlines the general requirements for 55% aluminum‐zinc alloy‐coated steel sheets in coils and cut lengths for applications requiring corrosion resistance or heat resistance or both. Included in this specification are steel chemistry requirements and typical mechanical properties of various metallurgical grades.
Coating Thickness
Coating thickness is measured as the coating weight in ounces per square foot. For example the coating designation AZ‐55 specifies there is a minimum coating weight of .55 ounces per square foot (total both sides) is equivalent to 0.8 mil thickness per side.
Surface Treatment
The “chem.‐treat dry” surface treatment consists of an application of a thin, invisible, corrosion inhibiting, inorganic chemical film on the surface. This film is applied at the galvanizing line by dipping into an aqueous solution of corrosion inhibiting chemicals.
Item Codes:
GU24G48120 24Ga 48″ x 120″ Galvalume AZ-55
GU18G48120 18 Gauge 48″ x 120″ Galvalume Sheets AZ-50/55
GU26G48120 26Ga 48″ x 120″ Galvalume AZ-55
GU24GA48 .023 min. x 48″ Galvalume Coil AZ-55
GUS^20G48110 20 Ga 48″ x 110″ Galvalume Sheets AZ-50
GUD24GA 24 Ga x misc. wide Galvalume Coil
AUS22G48120 22 Ga 48″ x 120″ Galvalume Plus AZ-55
GUS22G48120 22 Gauge 48″ x 120″ Galvalume Sheets AZ-50/55
GU^24G4896 24Ga 48″ x 96″ Galvalume AZ-55
GU^26G36240 26 Ga 36″x240″ Galvalume Sheets Type PBR
GU^20G48120 20 Gauge 48″ x 120″ Galvalume Sheets AZ-50/55
GU^14G48120 14 Ga 48″x120″ Galvalume Sheets AZ-50/55
GU^26G36216 26 Ga 36″x216″ Galvalume Sheets Type PBR
AUS18G48120 18 Ga 48″ x 120″ Galvalume Plus AZ-55
GU^26G48122 26 Gauge 48″ x 122″ Galvalume Sheets AZ-50/55
