Grit size is determined by mesh size
The basic principle when grinding hard materials such as steel is the same in all applications. Coarse pre-grinding is increased by subsequent runs with increasingly fine abrasives until the desired degree of severity is achieved.
The unit of measure for the grinding ability and composition of a whetstone is the grit number. The higher the value, the smaller each individual grain becomes. The basis for the valuation is the unit of measure mesh or mesh size. It derives the values from a sieve that theoretically would pass through single grains with the appropriate mesh size.
Three Scales of Grain Grades
There are three different mesh sizes used in international trade. A simple comparison is not possible because the values are not linear to each other. The three grain scales used are used following the origin of the honing stone. Europe, Japan and the USA share the market.
Some common European grain sizes can be "translated" using grain comparison tables. Typical examples are:
320- in Europe, equivalent to Japanese 600- and US-American 360 grit
- 400- in Europe corresponds to US 500 grit
- 500- in Europe equivalent to Japanese 1200 and US 600 grit
- 800 - in Europe corresponds to Japanese 3000 and US 1200 grit
- 1200 - in Europe corresponds to Japanese 4000 grit
- 2000 - in Europe corresponds to Japanese 8000 grit
- Useful grit ranges
The classic universal honing stones for home use usually have two sides. The grains of the coarse side range between 400 and 600 and the finer sides between 900 and 3000 according to European design. Household knives achieve sufficient blade fineness when sharpening up to 1000 grits. Cooking and razor should be finalized with 3000 grit.
Grains can lose up to one hundred percent of their effect due to untrimmed whetstones and dirt.
Tips & TricksWhen searching for your ideal honing stone, you should always focus on the finer side. The coarser grain should be about one-quarter to one-third of the fine grain. This applies to all three scales as long as they are compared with each other.