these bits drill into the wood very fast. the bit pulls into the wood while drilling. the 25 mm requires heavy torque by the drill. till now I have drilled only in softwood but they left a good finish. you have to limit the feed rate while drilling or else you need a very powerful drill. I am happy with my purchase. they are good quality considering what I paid for them. I recommend this product. I bought 5 different sizes from 8-25 mm to drill for long dowels. seller dispatched immediately and shipping was quite fast. I found lavie bits to be good quality. I bought a router bit of the same brand from same seller.