What's the Difference Between Flat and Countersunk Head Rivet Nuts?

From the tightening effect, the flat head rivet nut is better. But in some cases, the plate surfaces are required to flat and smooth after riveting, so you need to make a sink hole in the riveting process, and then use a countersunk head rivet nut, when the riveting is completed, the surface will be flat. However, the mechanical properties of a countersunk head round body rivet nut will be relatively lower than the flat head rivet nut.

From the mounting appearance, as the above indicated, flanges of the small countersunk head rivet nut is thinner, it is flat on the surface of the plate after riveting. However, flanges of the flat head rivet nut is thick, so to convex on the surface of the plate after riveting.