What does the designation MS20426AD-6-5 indicate about the rivet?

The designation MS20426AD-6-5 provides specific information about the rivet's type and characteristics. In this designation:

• The "MS" prefix indicates that it is a military standard part, which confirms its compliance with certain specifications and standards.

• The "20426" part points to a particular design and material specification for the rivet, specifically indicating it is a high-strength aluminum alloy.

• The "AD" indicates the type of head shape, which is a countersunk shape designed for flush fit applications. Countersunk rivets allow for a smooth surface, which is particularly important in applications where aerodynamic efficiency is necessary, such as in aircraft structures.

The "6" indicates the diameter of the rivet in 1/32 of an inch (in this case, 6/32 or 3/16 inch), and the "5" typically designates the grip length in increments of 1/16 of an inch.

Understanding this designation affirms that the rivet is indeed a countersunk rivet, suitable for applications that require a flush surface after installation. The other options do not align with the specific identification implied by the MS20426AD designation.