Pencil Hardness, Mohs Scale, ASTM D3363, 9H & 10H

Explanation Post about H – Hardness, Scales (Mohs Scale, Pencil Hardness), Standards (ASTM D3363 / ISO 15184) & Pencil Hardness test Pencils (9H/10H).

Hardness – Symboled with “H
Mohs – a mineral stones hardness scale (Diamond, Quartz, Opal, etc.)
Pencil Hardness – film (Ceramic Coatings / PPF / Paint) test method using the world standard ASTM D3363.

These scales are not similar! They both using “H” for Hardness but they are different.
Example: Quartz Hardness in Mohs scale is 7H, but in Pencil Hardness it can be 9 or 10H.
That’s why a Ceramic Coating Said that the ceramic coating hardness is 9H is not “one level below diamond” and is not “scratch resistant” (it is, but for 9H by pencil hardness scratches and not what we expect it to be).
BTW, If we will test by Wickers, so Mohs’s 9H will be stronger 2 times than the 8H, but the 10H (Real Diamond) will be stronger 4 (!) times than the 9H!

Our factory manufacturing 2 kinds of Ceramic Coatings: 9H & 10H.
We are not measuring with Mohs scale, we are not diamonds factory. We’re measuring by Pencil Hardness.

There are rumors saying that 10H is unmeasurable.
Those rumors are not right.
The ASTM D3363 standard does not limit any hardness of pencil. It just teaches us how to work with the machine and measure correctly.

Actually, 9H & 10H pencils are from the art industry. The more the H is higher, the brighter the pencil. The less, you get to the middle of the scale called HB. The more the B is higher (opposite of H), the darker the pencil.

You can get 9H & 10H Mitsubishi Pencils (Japan) for Pencil Hardness test from
Those Pencils are certified by test labs around the world for the standard ASTM D3363.