If you just want to use them for construction purposes on 2x4 etc they are perfect. The teardrop on the right threw a 2x4 with ease. Anything else will splinter or bind if it's a harder material. On materials like mesquite or plexiglass, the tip of the drill will chip/break or just jam completely. I wish I could give it more stars because they are REALLY good, just not for anything other than general construction.