Ceramic Knife Hardness

A ceramic knife is a knife designed with a ceramic blade typically made from zirconium dioxide zro 2.

Ceramic knife hardness.

They have a tendency of being really fragile says kilcher. For instance a harder steel with a rc of 58 62 will hold an edge better than a softer steel. The method for measuring the hardness of fine ceramics is defined in jis r 1610 iso 14705. Also known as zirconia.

However that same harder steel is less durable and more prone to chipping or even breaking. Neither steel or ceramic these knives are the perfect combination of hardness and strength whose extraordinary precision can be measured to light band tolerances. The zirconia powder used to manufacture these knives is dry pressed and then fired later. So and so s 9h ceramic.

The pencil hardness method was originally developed by pencil manufacturers as a quality control method in the early 1900 s. What are the disadvantages of a ceramic knife. I would be worried about chipping the blade. These knife blades are usually produced through the dry pressing and firing of powdered zirconia using solid state sintering it is 8 5 on the mohs scale of mineral hardness compared to 4 5 for normal steel and 7 5 to 8 for hardened steel and 10 for diamond.

The toughness of a ceramic knife is expressed in terms of the mohs scale of hardness. Hardened steel ranks from 7 5 to 8. Generally a knife with a rockwell hardness scale rating of 58 62 will hold an edge better than a blade that has a lower hrc rating. The blade is then sharpened by a grinding wheel coated with diamond dust.

It s a measuring system of non destructive metallurgical testing that determines how hard and strong steel such as that used in knife making truly is. While it is true that the extreme hardness of ceramic knives can keep them sharp for a long time it is this exact trait that creates some of the main disadvantages of ceramic knives. This is a very touchy subject as many companies have built their brand around the hardness rating. Steel is ranked at 4 5.

Let s start with a little background on both pencil hardness and the infamous mohs scale. Being made of such a hard material leads ceramic knives to be quite brittle and susceptible to chipping or breaking. With an outstanding hardness of hrc 71 simply put they re nothing short of the hardest and most durable knife blades that have ever been made. The hardness of fine ceramics is generally indicated using a vickers hardness number.

Japanese style knives tend to have hrc ratings of 60 and above. Some kitchen knives with high hardness require extreme care so that you do. Vickers hardness is a resistance value obtained by pressing a diamond indenter onto a test specimen. I think they re really cool i ve used a few of them but i probably shouldn t own one.

The most straightforward answer is that rockwell hardness refers to how resistant a metal object such as a knife blade is to penetration and permanent deformation from another material.