Rockwell Hardness Chart?

[sketchbag]

Does anyone know of a list showing the HRC of various items, like diamond, ceramic, ect?

 

[bearcut]

one word: Google

 

[Chimay]

http://www.agrussell.com/knife_information/steel_guide/index.html

 

[yablanowitz]

As far as I know, the hardness of diamonds and ceramics can't be tested by the Rockwell test. You will have to look for other scales of hardness such as the Vickers or Knoop scale to get comparative numbers. Knarfeng found one and put it up in this post: http://www.bladeforums.com/forums/showpost.php?p=5416701&postcount=13

 

[sketchbag]

Thanks for the links.

Yablanowitz, I wasnt aware of that, but upon considering how the rockwell test is done, i'm not surprised. That chart you linked is perfect, I wasnt as interested in everythings exact HRC value, so much as how hard they are in relation to each other, that chart really adds a lot of perspective. Cheers!

 

[yablanowitz]

I thought that might be what you were after. Glad to help.

 

[Jim Shultz]

I've been pondering this for a while: Would a lower RC blade scratch a higher RC blade? If not, one could use their various knives, with their known approximate RC range, to gauge the hardness of an unknown blade. Nicht var?

 

[HoB]

I've been pondering this for a while: Would a lower RC blade scratch a higher RC blade? If not, one could use their various knives, with their known approximate RC range, to gauge the hardness of an unknown blade. Nicht var?

Well you got the basic idea right, only that the higher Rc blade would scratch the lower, not the other way round. There are file sets for precisely that purpose, but the application takes a lot of practice and the precision is not very high.

 

[Nosetotail]

^ I think that is what he was saying, that if a lower RC steel didn't scratch a higher one, then a higher one could be used to test for RC hardness.

I'm inclined to think that even though a steel is softer, it would still be able to leave a scratch, but I wouldn't know.

 

[HoB]

You really have to klick over to the makers subforum to get advice on that. As I understand it, it is not so much that it doesn't leave a mark, but the feeling is different. You have a set of files with a predetermined hardness and you try them sequentially from the hardest to the softer ones. When the file starts to skate on the test piece, you know it is in the same ballpark. Some makers are supposed to be really good at it.

 

[knarfeng]

That is to say that the process becomes sensitive to the skill of the one performing the test if more than a rough guess at the hardness is desired.