The Original Work Sharp knife sharpener is usually sold with 6 belts, 2 of each grit (80grit, 220 grit and 6000 grit). An additional box of mixed belts also includes the same 6 belts. The company says that these 6 belts (used with the Original Work Sharp) will usually sharpen anywhere from 50 to 200 knives. The factors that determine how long the belts last are: size of knives, hardness of steel and the condition of the knives (how dull, damaged, etc.).

The Ken Onion Edition of the sharpener includes 5 different belts, one belt of each grit (P120, X65, X22, X4 and 6000). Ken Onion states that three of the included belts (the X65, X22 and X4) are pro-level Norton Norax belts, the same belts he uses on his big machines. He further states that they will continue to work until you’ve worn them down to the cloth backing. My experience is that the belts included with the Ken Onion Edition will sharpen more knives than the belts included with the Original Work Sharp. But with either machine, the time it takes to get a knife sharp will lengthen as the belts wear.