The powdered aluminum additive strengthens the resin.........at least from my testing standpoint. I cast drive sprockets in both regular and aluminum added resin, then applied presure against both and also tried to bend and break both. The reinforced was much tougher. It took pliers pulling two ways to really rip them apart. So far the reinforced sprocket teeth have held up well interfacing with the plastic tracks, and I have quite a few hours of run time on them. I can report better later on after FRAG holds a few battles. PP