I would highly recommend this specific type of drill bit, brand i couldnt tell you. I have heard nothing but good about these bits, and i brought one myself was awesome, as Simon said, keep them cool and drill on a slow speed.
There was only really one thing I found could have been better with this bit, it was rather short (perhaps for more strength, i don't know) so for example when I was drilling the tie hooks on my ute tray, it was a little tight, still worked with a bit to clear but tight....
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I havent had experience with these drill bits myself, however when i did the research on a spot weld drill bit there was nothing but comments on short lifespans and braking chipping teeth...
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