Review on Amana Tool 51441 K Spektra Plastic by Anthony Morrow

I really like how this bit cuts aluminum and acrylic composites. I had to slow down the feed and speed on the acrylic but it still cuts great. I consider helical O-shaped single grooves only as a semi-finish cutter because they don't seem to give the correct finished size unless I make 3 or 4 passes each approaching the correct size. I usually just make one pass with a spiral O-shaped single groove and then another pass with a double groove flat cutter which gives me the right size fine cut. These bits also leave a smooth finish on the side edges of the material.