The higher the grit of a honing stone, the sharper it grinds. The increase in grit value describes a larger number of increasingly smaller abrasive particles. Coarse grits start at 240 and the finest honing stones have grit values up to 3000. 1000 grits already produce razor-sharp cutting edges.
Grit size is determined by mesh size
The basic principle for grinding hard materials such as steel is the same in all applications. Coarse pre-grinding is increased by subsequent passes with increasingly finer abrasives until the desired degree of sharpness is achieved.
The unit of measurement for the grinding ability and composition of a honing stone is the grit number. The higher the value, the smaller each individual grain. The basis for determining the value is the unit of measurement mesh or mesh size. It derives the values from a sieve that, with the appropriate mesh size, would theoretically allow individual grains to pass through.
Three scales of grain size
In international trade, there are three different mesh sizes that are used as a basis. A simple comparison is not possible because the values do not relate linearly to each other. The three grit scales used are based on the place of origin of the honing stone. Europe, Japan and the USA share the market.
Some common European grit sizes can be “translated” using tables for grit comparisons. Typical examples are:
- 320- in Europe corresponds to Japanese 600- and U.S. 360- grit.
- 400- in Europe is equivalent to U.S. 500 grit.
- 500- in Europe corresponds to Japanese 1200 and U.S. 600 grit
- 800- in Europe corresponds to Japanese 3000 grit and U.S. 1200 grit
- 1200- in Europe corresponds to Japanese 4000 grit
- 2000- in Europe corresponds to Japanese 8000-grain size
Useful grit ranges
The classic universal honing stones for private use usually have two sides. The grits of the coarser side range between 400 and 600 and the finer sides between 900 and 3000 according to European measurements. Household knives achieve adequate blade fineness when sharpened to 1000 grit. Chef’s and razor knives should be finalized with 3000 grit.
Grits can lose up to one hundred percent of their effectiveness due to non-dressed whetstones and dirt.
Tips & Tricks
When looking for your ideal honing stone, always go for the finer side. The coarser grit should be about a quarter to a third of the fine grit. This applies to all three scales, as long as they are compared to each other.