What are the dimensions of an MS20 430 AD 4-8 rivet?

The correct answer provides the dimensions of the MS20 430 AD 4-8 rivet, which has specific standardized measurements. In aviation and engineering applications, rivets are designated by a series of numbers and letters that indicate their characteristics, including diameter and length.

In this case, "MS20" signifies the rivet's specification, "AD" indicates the material and intended use (typically aluminum alloy), “4” represents the diameter in 32nds of an inch, and “8” refers to the length in eighths of an inch. Therefore, interpreting these details reveals that the rivet is indeed 1/8 inch in diameter and 1/2 inch long, confirming that the first choice is correct.

This systematic approach to rivet designations is crucial for ensuring compatibility and safety in aircraft construction and maintenance, as using the wrong type or size of rivet could compromise structural integrity. Understanding these designations allows for accurate identification and selection of rivets for specific applications, ensuring adherence to stringent aviation standards.