An 8 gauge aluminum sheet refers to the thickness or gauge of the sheet metal. The gauge number represents the thickness of the metal, with a lower number indicating a thicker sheet. However, the specific thickness of an 8-gauge aluminum sheet can vary depending on the manufacturing standards and country of origin.

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, an 8-gauge aluminum sheet typically has a thickness between 0.1285 inches (3.26 mm) and 0.1443 inches (3.67 mm).