Purchased for drilling Mountain Cedar TX center logs. (actually ash juniper, a hard, oily wood). These drills could not penetrate these "cedar" trunks, they just ground the trunk until it smoked. Used a fairly new heavy duty DeWalt 1/2" corded bit so power wasn't an issue. Tried the same bit on a piece of standard 2x4 pine and it drilled through with no problems. Went to the local Ace hardware store and shopped Pair of 8" DeWalt bits that did the trick and got me through the day. Bottom line: these bits are good for soft materials but only good for lighting hard wood!