Definition cutting resistance of porcelain
First of all it has to be pointed out that the cutting resistance of porcelain and ceramic tableware - as well as the classification "dishwasher-safe" is not exactly defined in a DIN-NORM e.g.. In fact the term cut resistance even has two meanings. Vegetables (tomatos) which are easy to cut have a good cutting resistance. For porcelain and ceramic tableware a good cutting resistance is achieved when the porcelain is not cuttable.
So cutting resistance of porcelain and ceramic tableware means that the surface is not damaged while cutting food on it. The English definition "cut resistant" is describing this feature closer than the German one. If you add "resistance to scratches and abrasion" it is clear definition of cutting resistance of porcelain.
Cut resistance is a local assessment
Germany is well known for Bread, Schnitzel and Haxn, Italy for Pizza, Spain for Parillada. The biggest part of the european dishes is cutted on plates. This is why a better cutting resistance is requested in Europe compared to other regions where a cut resistance is not needed. In China alles dishes are consumed with chop sticks, in Thailand with spoon and fork, in Pakistan, India and Bangladesh most of the dishes by hand. In view of the total global population a cutting resistance is only requested by a small part of it. This is why there is currently such a big part of tableware on the market which does not have any cutting resistance.
For our customer cutting resistance is playing an import role. So we need to ensure that the goods we are providing do ensure a good cutting resistance. Only in some small parts of our assortment e. g. mediterrean stoneware or porcelain in slate design we can only guarantte a lower cutting resistance due to manufacturing reasons.
Cutting resistance of Holst Porzellan/Germany
Holst Porzellan/Germany defines cutting resistant based on the following facts:
Regarding this figures we think that a test with a drawing pressure of 500 g is not representing reality. In our test we double the drawing pressure to 1.000 g. Like in the test for tires we generate a tolerance and increase the drawing pressure to up to 1.300 g for 20 cuts on one and the same point.
This is how we test the cutting resistance for our assortment:
In the following video you can see our test method for High Alumina Porcelain
Cutting resistance and new cutlery
New cutlery which has not been washed can have some residuals from the manufacturing process on the blade, which can cause abrasion on porcelain. During the first weeks of use cutlery develops a patina which closes the surface and additionally hardens it. Until the patina is built it is possible that the cutlery gets rusty or leaves residuals on the porcelain. After the patina is built there will be only small changes in the general condition of the cutlery and there is no abrasion on porcelain anymore.
The smaller the part of the chrome in the cutlery, the bigger the probability of abrasion by the blade. Before the 1990s it was not possible to produce monoblock-knives with a 18/0 blade. Only knives with a hollow handle had a blade made of 18/0. With this knives there were occuring almost no problems with abrasion. Since some years only it is possible to produce monoblock-knives made of 18/0, which have a better cutting quality and due to higher hardness do not cause abrasion.
From the above lecture, it can be seen that a self-conducted test to check the cut resistance of porcelain should never be made with "brand new" cutlery, e.g. should be performed from the model shelf. Practice has shown that even in our high-quality High Alumina Porcelain unused cutlery on the surface creates abrasions that are exclusively due to polishing residues or missing patina. However, this abrasion can be removed easily with good detergent or porcelain cleaner again.
Incidentally, the risk of glaze corrosion can also be derived directly from the cutting resistance of porcelain and tableware. Please also read our contributions