I got a really nice new Sharkbits down cut endmill for Christmas. I bet it would have worked great for wood. Not so much on aluminum when you are too dumb to read the packaging and think it is your up cut. By the way the up cut (on the left) worked way better. Almost like it was intended to be used for this purpose. I blame @pedrofernandez because I am cutting the aluminum plates for my copy of his rotary axis for lasers. It is a great design.