These crowns may seem cheap, but don't let that fool you. They're probably tougher than you or your drill bit. I had to install a dryer vent through aluminum trim and a 3/4" pad and was surprised that the 4" hole was perfect in every way. After the saw cooled I checked the teeth and it didn't look like there were many. Signs of wear The paint has peeled off, but that's the only sign of wear that impresses me.