how hard is hard?

[duane roy]

Is there a simple way to find out how hard a blade is? Using the old file skipping across the surface or the very little sparks from a grinder is kind of guessing. There must be a simple way tp approximate how hard (Rockwell, I guess), something is?

 

[Chiro75]

Short of actually having the blade tested, the file method is pretty accurate.

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My Custom Kydex Sheath pagehttp://www.geocities.com/CollegePark/Lab/1298/knifehome.html
Palmer College of Chiropractic
On Two Wheels

 

[george tichbourne]

The other way is to use scrapers of known hardness and test until there is a scratch left by the scrapers. Some machinist supply outlets sell graduated files to check hardness but they are not highly recommended by heat treaters because they are not too accurate.

I prefer to let my heat treater check the hardness for me on proper equipment. I have watched during the test and results are almost always right on or a point over.



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george
www.tichbourneknives.com
sales@tichbourneknives.com

 

[tom mayo]

actually....its the Rockwell c scale...Rc that is used to measure metal hardness... they have other scales for other things.... rocks are not measured like steel....it is just a standard of measurement....measuring how far a diamond stylus penetrates a known steel type with a certain weight....there are innummerable other things to consider... especially when heat treating is thrown in.. and so we just have a relative measurement.. like ones weight...it tells us how heavy we are here at sea level.....but thats about all, in comparison to water or something... its just a thing to help us....it is just a small part of the puzzle....

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http://www.mayoknives.com

 

[Darrel Ralph]

There is a set of hardness files that you can buy. They have a range I believe from the 30's - 60 rc. Just test with thenm to tell where you are on the scale. I agree with the old file test just as well. If you get the right dull file you can tell fairly easy

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Web Site At www.infinet.com/~browzer/bldesmth.html
Take a look!!!

 

[Pete Peterson]

all good advice, but keep in mind that each steel has it's own best hardness point for each application. for instance a carbon steel like 5160 or stain resistant like ATS34 will perform best at one hardness for a big camp knife, but for a small hunter or a folder that "best performance" point will be a little different. Don't we live in an
interesting world !!!!

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old pete