When is the full shear strength of an MS20470D rivet obtained?

The full shear strength of an MS20470D rivet is attained after a period of aging. This aging process allows the rivet material to develop its maximum strength characteristics, which typically occurs as the rivet's material undergoes changes that enhance its mechanical properties over time.

Many aluminum alloys used in rivets go through a phase where they gain strength as they age, especially if they were heat-treated prior to installation. This aging process can involve natural aging or artificial aging, depending on the type of alloy and the conditions it has been subjected to.

Achieving full shear strength immediately upon installation is not accurate because the rivet must allow time for the material properties to stabilize. Similarly, the notion that full strength is reached after 24 hours or during the first flight does not consider the specific metallurgical processes involved in the aging of rivets, which are crucial for ensuring they reach their optimal strength in service.