The purpose of this article is to provide information about the advantages and disadvantages of a mirror-edge, and provide a selection of recommendations for grit progressions to achieve a mirror-edge.
Push-cutting - Highly refined, polished edges outperform toothy edges at tasks which involve push-cutting. Some examples of those tasks are:
Using a chisel or plane blade
Less friction - An edge with a very high polish will experience less friction when cutting. Because the bevel is smooth, it will glide through the object being cut, without producing resistance.
Clean cuts - Polished edges create cleaner cuts in delicate foods like fish and fresh produce. These edges don’t tear or crush the food, producing better tasting and better looking dishes. Studies have shown a significant reduction in oxidation to food surfaces when they are cut with a highly polished blade versus a blade with large micro-serrations.
Aesthetics - Many people find mirror-edges to be aesthetically pleasing, so this type of any edge can add value to knives.
Objects with a hard, smooth exterior, like cardboard, zip-ties, tomatoes, bread with a hard crust or packing tape are more resistant to highly-refined edges. A less refined finish is better at cutting these objects because there are micro-serrations on the edge of the blade that will bite into the object being cut.
Is it possible for a knife to have a mirror edge and perform well at everyday cutting tasks? It is with micro-bevels!
Adding micro-bevels to a knife is an excellent way to produce a great looking edge with less friction while cutting, that is also very effective for everyday cutting tasks like boxes and tape, rope and tomatoes. Start by establishing the bevels and then polishing them at a lower angle than you’ll want for your final edge (these are called the primary bevels.) Then simply widen the sharpening angle by 3-4 degrees and make a few, very light passes with a coarser stone (these are called the secondary or micro-bevels.) Here’s an example: Sharpen the knife at 20 degrees using one of the abrasive progressions listed below to create a mirror finish. Then, widen the angle on both sides of the knife to 23 degrees, and make 5 light passes with the 1000 grit stones. This will create a secondary bevel at the apex of the edge that’s barely visible to the naked eye, and will have micro-serrations that will bite into whatever you’re cutting.
Creating a Mirrored Edge in Ten Minutes on the Wicked Edge