Noble, how much power do you have on your mill? The .055 blades cut like a house'a'fire but takes a lot of power to pull them.
First one we tried cut over 2,000 bf of red oak and was still cutting good when it broke. I talked to WM and they said I had ran it too long. Should stop and have it sharpened so to remove any stress cracks starting in the bottom of the tooth. Said not to expect as many sharpenings.
Can't complain, even though it broke, it still only cost me .01/bf.
I changed sooner on the other .055 blades and got a couple of re-sharps out of them and still using them. But mostly, we run the .045s.