Calculating the Bevel Angle for the Knive Blade


Calculating the Angle of the Bevel

To calculate the angle of the bevel we need to do some trigonometry - Yes, we are actually going to need to use math. To calculate this angle you first need 2 measurements -

  1. The height that you would like the bevel and
  2. How deep you are going to cut the bevel into the knife - see image above.*Important, you need to leave about 1mm(3/64ths) not removed from the blade of the knife (Don't worry, you will grind that sharp later as your Primary bevel/cutting edge).
  3. Now, Divide the depth of the bevel by the height of the bevel. Don't worry, you will end up with something like 0.0876.
  4. Go to this website and enter the number that you calculated into the Inverse Tangent Calculator, and click Calculate.
  5. Make note of the number of Degrees that it is calculated as. 0.087 came out as 5.0063 degrees - so I will just round to the nearest 1 decimal. e.g. 5.0 degrees.
  6. Set up the Blade grinding JIG to 90 degrees PLUS the angle that you calculated. E.g. 90 + 5 = 95 degrees.
  7. Go ahead and grind the bevel - make sure that your teacher has checked your calculations, how you rigged the blade in the JIG and how you should now grind the bevel.