Ceramic Knife Hardness

The toughness of a ceramic knife is expressed in terms of the mohs scale of hardness.

Ceramic knife hardness.

Being made of such a hard material leads ceramic knives to be quite brittle and susceptible to chipping or breaking. Hardened steel ranks from 7 5 to 8. The hardness of a knife is very important as far as its performance and durability. They have a tendency of being really fragile says kilcher.

So and so s 9h ceramic. 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. I think they re really cool i ve used a few of them but i probably shouldn t own one. 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.

Vickers hardness is a resistance value obtained by pressing a diamond indenter onto a test specimen. Neither steel or ceramic these knives are the perfect combination of hardness and strength whose extraordinary precision can be measured to light band tolerances. Some kitchen knives with high hardness require extreme care so that you do. The pencil hardness method was originally developed by pencil manufacturers as a quality control method in the early 1900 s.

The zirconia powder used to manufacture these knives is dry pressed and then fired later. The method for measuring the hardness of fine ceramics is defined in jis r 1610 iso 14705. 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. A ceramic knife is a knife designed with a ceramic blade typically made from zirconium dioxide zro 2.

Let s start with a little background on both pencil hardness and the infamous mohs scale. This is a very touchy subject as many companies have built their brand around the hardness rating. The hardness of fine ceramics is generally indicated using a vickers hardness number. What are the disadvantages of a ceramic knife.

However that same harder steel is less durable and more prone to chipping or even breaking. 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. Japanese style knives tend to have hrc ratings of 60 and above. Steel is ranked at 4 5.

I would be worried about chipping the blade. The rockwell hardness test allows knifemakers to find a balance that promotes blade sharpness and helps the owner keep it that way. For instance a harder steel with a rc of 58 62 will hold an edge better than a softer steel. The hardness that makes ceramic knives incredibly sharp and resistant to wear also makes them susceptible to chipping or breaking.

Also known as zirconia.