A 12 ga aluminum sheet refers to a specific thickness or gauge of aluminum sheet metal. The gauge number represents the thickness of the metal, with a lower number indicating a thicker sheet. In the case of a 12-gauge aluminum sheet, it is thinner compared to a lower gauge number.

In the United States, the Aluminum Association (AA) standard provides a range of thicknesses for aluminum sheets based on gauge numbers. According to the AA standard, a 12-gauge aluminum sheet typically has a thickness between 0.0808 inches (2.05 mm) and 0.0907 inches (2.30 mm).

12 gauge aluminum sheets are commonly used in various applications due to their versatility and lightweight nature. Aluminum is a popular choice for sheet metal because it is lightweight, corrosion-resistant, and has excellent conductivity properties. It is widely utilized in industries such as construction, automotive, aerospace, and electronics.