Knife Sharpening Angles Explained
Angle affects cutting feel and edge robustness, but steel, heat treatment, blade geometry, and use matter too.
Angle Per Side Versus Included Angle
An angle described as 15 degrees per side produces an approximately 30-degree included angle for a symmetrical double-bevel edge. Always check which convention a guide uses.
Start With The Knife
The knife maker’s recommended geometry is a safer starting point than copying an angle from a different blade. A narrower edge is not automatically better for every task.
Using A Guided Machine
The Tormek US store describes adjustable angles of 8–22 degrees per side for its kitchen sharpening systems. Confirm your blade fits the guide and follow the manual. Tormek US product information.
When To Change An Angle
Reprofiling an edge removes more metal and can alter its behavior. Make changes deliberately and avoid unnecessary grinding.
An Example Without A Universal Rule
A symmetrical edge sharpened at 15 degrees per side has an included angle of about 30 degrees. A 20-degree-per-side edge has an included angle of about 40 degrees. These figures describe geometry, not a promise about how long a particular knife will stay sharp.
Match The Existing Bevel First
When you do not know the intended angle, inspect the existing bevel and seek the maker’s guidance. Changing to a much narrower angle can remove substantial material and may produce an edge poorly suited to the knife’s tasks.
Special Cases
Single-bevel and asymmetrical knives cannot always be described by one angle on each side. A standard symmetrical guide may not preserve their geometry. Confirm the blade type before applying advice meant for ordinary double-bevel kitchen knives.
What If The Two Sides Differ?
Some knives are intentionally asymmetrical. An angle guide that assumes equal settings on both sides may change the original geometry. Record or verify the existing bevels before sharpening, and use an appropriate method if the blade cannot be supported correctly.