I recall we were discussing slitting saw arbors a while back. Now I've used mine a few times over the years. Since there isn't a key for it I made sure I tightened it really well. The hex head allen wrench was all of maybe 2" long. Suddenly snap. Manage to catch the blade. Only a few scratches on my knuckle. Could have been a lot worse if it happened while the holder was spinning the saw.