Two metal beams are joined together by four rivets?

Question

Each rivet has a radius of 4.8 x 10^-3 m and is to be exposed to a shearing stress of no more than 5.1 x 10^8 Pa. What is the maximum tension T that can be applied to each beam, assuming that each rivet carries one-fourth of the total load?

Answer 1

Am I missing something?

There are 4 of them and each can resist a shearing stress of 5.1 x 10^8 Pa. So why not multiply that times 4?

Unless you are looking for a material these rivets are made...