I am installing a urethane rail and baluster system that has a 1 1/2 square alum. tubing in the center. Having trouble  drilling the holes for balusters, hole saws are wearing out quickly and a pain getting the plugs out . Was wondering about  a step drill or cone drill I need a 3/4 hole for the balusters,I have about 200 spindle to put in. I only got in about 45 today. Also I will have to scribe the rails into 12 in. round columns on the first floor porch is there a router bit that can cut the alum. I just finish another rail and baluster system from the same company that was larger in size it had pvc pipe in the center, I could cut this with a router. Any advice will be greatly welcome.  thanks