I noticed people often hasn't the slightest idea of the amplitude of angles.Ok, the tool for turning steel has a rake angle¹ of 12°, but how much is it?Look at the watch dial!15 minutes make a 90° angle, thus every minute the hand moves of 6°, and the rake angle above is the same of 2 minutes.Easy, isn't it?Of course this doesn't work on digital watches.~~¹ https://en.wikipedia.org/wiki/Rake_angle