I'm trying to install aluminum rivet nuts for some 8-32 hex screws. I don't have the special tool so I'm trying to do it with a nut and 2 wrenches. The problem I'm having is that the screws keep keeps sheering off at the nut (they're stainless but I don't know what their rating is). Does this mean that a #8 screw can't handle the tension needed to collapse the rivet? Is there anything else I can do (besides splurging on the proper tool)?