OK, back to your question...the 6061T3 is a specification for aluminum material on the heat treating. Generally a spec for aluminum sheets and other structural components. Just get solid aluminum rivets and they will work just fine. The length will be the thickness of the material being fastened together plus 1 1/2 times the diameter of the rivet, This allows for the bottom of the rivet shaft to flatten correctly and provide for a good grip.
Sorry for the delay in answering, had several issues to take care of.
Sorry for the delay in answering, had several issues to take care of.
