Frequently Asked Questions

Our extensive blade use and sharpness testing have taught us that a convex edge is a superior edge. The smooth radius edge type does not have ‘shoulders’ like a flat grind and thus has less friction or resistance when cutting. A convex edge provides more steel behind the edge to support it, so the edge stays sharper longer. Lastly, our convex method thins the edge when you sharpen the blade, while flat ground blades get thicker and thicker as you re-sharpen.

Most Asian style knives are manufactured between 14°-16° and most European style knives are manufactured between 20°-22°.

Work Sharp Culinary standard guides create a 17° bevel on each side of the blade. Our testing has shown this is optimal for the keen cutting of an Asian style knife, while maintaining the durability of a European edge.

Expandable sharpening capabilities are available for the E5 sharpener with the E5 Upgrade Kit (sold separately). The E5 Upgrade Kit provides additional angle guides to maintain traditional edge geometries found on classic Western and Eastern knives.

Our research has shown that 17° is an optimal cutting edge, providing keen cutting control and durability. Changing the angle to 17° will continue to provide optimal cutting performance. If you prefer to maintain a 20° edge, the E5 sharpener has an optional set of 20° West Guides available with the E5 Upgrade Kit.

The ceramic rod included with the E5 and E3 sharpeners are set at 20°. The angle guide on the M3 is set at 17°.

The higher angle on the rod was designed to create a microbevel when used after sharpening with the 17° standard guides on the electric sharpener.

A micro bevel is a very small tertiary angle along the cutting edge of your knife. The wider angle provides strength and edge stability. A micro bevel will stop your knife edge from rolling or chipping as easily during use.

If your rollers begin to show wear and tear, please contact our customer service line at 1 (800) 418-1439 or visit

Refer to the “How to Change a Belt” section in your User Guide. User Guides can be viewed or downloaded from the “How to Use Your Sharpener” page.

The Ken Onion Sharpener was designed with a different tensioner than our Culinary Knife Sharpeners. We recommend using the specified belts for each product to avoid any damage to the machine or your knife.

For best results, always finish the complete cycle. If you stop the machine, start over in the preferred stage.

No. MicroForge does not support that type of blade.

Yes. MicroForge is an optional edge finish that can be removed at any time by using the red belt in Shape stage on the electric sharpeners, or by sharpening with the diamond rod on the M3.