Power
Drive power installed in an electric grinding machine. The indicator is expressed in watts. The larger and harder the tool being processed, the more powerful the electric sharpener is needed. However, for sharpening knives at home, a power level of up to about 450 W, or even less, is quite sufficient.
Sharpening / grinding levels
Number of levels of sharpening and/or grinding of knives. In basic models there are often few of them - rough sharpening, grinding and polishing, nothing more. Sharpeners with a large number of levels are less common and often cover the advanced or professional segment.
Min. grain
The smallest grit provided in the design of the sharpener or among the complete replacement whetstones. It also indicates the standard grain size for models that have only one type of abrasive surface.
The universal unit for grit is GRIT. Simplified, GRIT grit can be described as the smallest number of holes per square inch of a sieve, at which individual abrasive grains can no longer wake up through this sieve. Accordingly, the higher the GRIT number, the finer the grain will be and the lower the granularity will be.
The purity and intensity of sharpening directly depends on this indicator. The finer the grit, the finer the finish and the lower the abrasive performance, and vice versa, coarser surfaces are well suited for initial sharpening, roughing and/or removing large amounts of material.
Here is a rough table of recommendations for optimal GRIT grit for different applications:
80 – 600 — peeling work (for example, correcting the thickness or geometry of the cutting edge or the entire blade).
600 – 3000 – preparatory work (elimination of traces of peeling), initial sharpening.
3000 – 6000 – semi-finish and fine sharpening.
More than 6000 – final finishing, polishing, straightening of the cutting edge.
At the same time, it is worth remembering that the processing features also depend on the material of the abrasive (see above). For example, ceramic surfaces with
...the same grain size work more delicately and more slowly than diamond ones. More detailed recommendations on optimal grit values and the specifics of various materials can be found in special sources.Max. grain
The largest grain size of the abrasive surface provided in the design of the sharpener (or among the replaceable whetstones supplied as standard).
See “Min. graininess" above. This parameter is indicated only if the sharpener has several abrasive surfaces with different grain sizes. The greater the difference between the minimum and maximum graininess, the more universal this model is, usually, the more options it offers in terms of processing intensity. On the other hand, a wide variety of abrasive surfaces has a corresponding effect on the cost.
Weight
The weight of the item, expressed in grams.
A lightweight design is convenient for handheld and pocket sharpeners (see "Type"), as it allows for extended use without fatigue if the sharpener is meant to be held in the air. On the other hand, heavier weight is typical for stationary devices, which need to maintain stability during the jerking motions of knife sharpening.
