I bought a few Cherry Max rivets this week to use on the cargo ribs to bulkhead. I got them from Aircraft Spruce. Their web site is very good and includes a table showing what grip length range each rivet is good for. They don't match the length number with solid rivets. For example a -4 solid rivet is not replaced by a -4 Cherry Max rivet. The Cherry Max rivets are good for a range of about a 1/4 inch. For example to fasten three pieces of .032 aluminum uses a -2 length Cherry Max because the -2 is good for about .068 to .120.