Copper cable lugs come in a wide variety of sizes depending on cable cross-sectional sizes and application specifications. Copper cable lug sizes are usually determined by the cross-sectional area of the conductor in square millimeters (mm²) and the stud hole diameter, which is equivalent to the bolt or terminal size in the connection. The standard sizes for copper cable lugs begin... https://www.pioneerpowers.com/copper-cable-lugs.php