All knife edges become dull with use, even edges on serrated or “never need sharpening” knives. This is because, with use, the edge eventually folds over or breaks when it encounters the resistance of the food being cut or when it comes into contract with a cutting surface.
Edges on conventional, hollow ground knives are weak and become dull much faster than double or triple bevel edges, which are formed by using a 2 or 3 stage knife sharpener.
The images below show what a dull edge looks like on conventionally sharpened and serrated knives.
The Secret to Keeping Knives Sharp Longer
The best way to sharpen a knife is to invest in a quality knife sharpener. Chef’sChoice® recommends using a multi-stage sharpener (electric or manual) with pre-set guides (to ensure angle control) and diamond abrasives, which will sharpen any metal alloy and never overheat/detemper the blade.
The secret to keeping your knives sharper longer is to make sure they are made from high strength steel and then to create an edge that resists folding. The strongest edge (shown above) is multiple-angled on both sides, which provides more metal to support the cutting edge. This stronger, longer lasting edge is obtained by using a multiple stage sharpener.