I have drilled over 500 holes with the same bit and have never had a problem. I drill 8 to 10 holes and then let the bit cool down, I insert the bit into the guide and bring it up to speed before contacting the wood, I also back it up a bit two or three times to clear the wood chips. And finally I always clean any wood sap off the tip before I put it away. I use the porter cable 20v cordless on the number 2 speed setting. I hope this helps.