How is the diameter of a 4-4 rivet measured?

The diameter of a 4-4 rivet is measured in 1/32nds of an inch. This measurement system is part of a standardized numbering system used to classify rivets based on their diameter.

In the case of the rivet numbered "4-4," the first number refers to the diameter classification, which is typically associated with a specific size. The diameter is expressed in 1/32 inch units, meaning that a 4-4 rivet has a diameter of 4/32 inches, which simplifies to 1/8 inches. This system allows for precision in determining the appropriate size of rivet needed for various aerospace applications, ensuring the correct fit and structural integrity.

Although the other measurement options like millimeters, inches, or 1/16ths are common, they do not apply to the standard rivet sizing system that specifically uses the 1/32nd measurement for many aerospace fasteners.