You won't believe how hard it is to find a top end drill this good. I thought a drill was a drill but it was I didn't.I returned the Irwin bit I got locally because it could barely drill through spruce and the Vermont American bit I got could at least get the job done but it just didn't feel like it too sharp on. I have tried at least one other brand. with the same results. For some reason this is the only 5/16" crown that actually works as it should. I am a professional carpenter and use this size often so it's important that it does its job so I bought 10 of these They are also surprisingly hard to find as those 10 pieces came from elsewhere as Revane didn't have them.