I have a 12 1/2" used thickness planer. Using it to plane oak. Don't have any experience with planing but the blade did get a slight nick after about 20 boards so I did not give it a 5 rating. This may be normal when planing oak with knots so may be it deserves a 5 rating. The price was good, shipping was fast, so I will order again if blades wear totally out. Ps, the blades do have 2 edges but I have not flipped them yet as the nick is quite small.