I mostly use olsen blades because they are easily available to me, whenever I buy blades I have never really paid any attention to tpi but maybe I should I have never really found that very important, I mostly use #2 and #5 blades and sometimes larger for thick wood, Another reason you could be breaking blades is if the wood you are using is too thick, I mainly use 1/8inch to 3/4 inch any thicker than that tends to be hard to cut