12 gauge aluminum refers to an aluminum sheet or wire with a specific thickness. In the gauge system, a higher gauge number represents a thinner sheet or wire. The gauge system is commonly used to measure the thickness of various materials, including metals like aluminum.

In the case of aluminum, a aluminum 12 gauge sheet or wire is approximately 0.081 inches or 2.06 millimeters thick. It's important to note that the actual thickness may slightly vary depending on manufacturing tolerances and standards.

Aluminum of this gauge is commonly used in a variety of applications, including construction, automotive, electrical, and manufacturing industries. It can be used for roofing, siding, gutters, electrical wiring, and other applications where a lightweight and corrosion-resistant material is desired.

In addition, the specific application and suitability of a 12 gauge aluminum will depend on the requirements and specifications of the project. It's always recommended to consult with professionals or suppliers to determine the appropriate gauge and type of aluminum for your specific needs.