Find the angle your knife was made for.

Per side versus the whole edge

Knife sharpening angles are often described per side. A symmetrical double-bevel knife sharpened at 15° per side has an included edge angle of about 30°. Always check how your knife maker expresses its guidance; a total angle and a per-side angle are not interchangeable.

Some knives have asymmetric or single-bevel geometry. A general-purpose magnetic roller setup should not be assumed suitable for those knives.

A smaller number is a tradeoff

A more acute edge can reduce resistance through food but may be more vulnerable to rolling or chipping, depending on the steel, thickness behind the edge, heat treatment, and use. A wider angle can support a more robust edge. Neither choice guarantees sharpness or durability by itself.

For example, 15° and 20° per side are commonly discussed kitchen-knife angles. The EdgeRoll guide is marked 12°, 15°, 17°, 19°, and 22°; choose a position only when it matches the recommendation for your knife.

The best starting angle is the one recommended for your knife.

Preserve the intended geometry

Start with the knife maker’s recommendation. Choosing a different angle may reprofile the bevel, which removes additional metal and can take substantial work. A multi-angle magnetic sharpener gives you positions to choose from; it does not make every position appropriate for every blade.

The five positions marked on the EdgeRoll guide are 12°, 15°, 17°, 19°, and 22°. If the supplied positions do not match your knife, choose an appropriate method or consult a professional.

Check contact and clearance

Angle choice is only part of the setup. The blade must grip securely and sit with the edge accessible. A narrow paring knife, a tall blade, a thick bolster, or a sweeping tip can change how the abrasive reaches the bevel. Never force the roller into the handle or base.

If contact looks uneven or the blade moves, stop. Do not compensate with more pressure. The rolling method guide explains the checks before sharpening.