For which size cleco fastener is green the corresponding color?

The green color of cleco fasteners corresponds to the 1/4 inch size. Cleco fasteners, commonly used in aircraft assembly to temporarily hold panels and components together, are available in various sizes, each designated by a specific color for easy identification. The standard color-coding system enables mechanics to quickly distinguish between different sizes in a busy work environment, ensuring efficiency and accuracy.

For example, while other sizes are also associated with different colors—such as black for 1/8 inch, red for 3/16 inch, and yellow for 3/32 inch—green is specifically reserved for the 1/4 inch cleco fastener. Knowing this color-coding system is essential for aviation structural mechanics, as using the wrong size can lead to improper fit, structural weaknesses, or difficulties during assembly.