BM Rockwell test

N

notos&w

Joined
Jul 17, 2002
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650
did a rockwell hardness test on my Benchmade 771 tonight. On the Rockwell C scale it measured an amazing 74! far more than the advertised 59-61 of the 154CM
 
Can someone who know tell me... Is that even possible???

Ahh dude, I don't thinks that possible but we'll know soon. This place is a wealth of knowledge! ;)
 
Knife11 :

Is that even possible???
Click to expand...

No. There are steels that can get in that range, but Benchmade is not using any of them. For example CPM-REX 121 can get to 70+ RC after tempering.

-Cliff
 
Thanks Cliff !! ;)

SEE DUDE I TOLD YOU !!! NOT POSSIBLE!!!

I'm just funnin' with ya but maybe you can tell us how you did the test of give us a link. These guys (and sometime girls too) can help you!

See ya round :cool:
 
Could a blade coating cause a higher hardness rating? Some of those coatings are pretty hard, aren't they?
 
Yes the coatings are very hard, they have to be ground off to a flat surface before you can get an accurate reading.

-Cliff
 
You may also wish to make sure that the testing machine is properly calibrated and that it is being used properly.
 
Originally posted by Ron@SOG
You may also wish to make sure that the testing machine is properly calibrated and that it is being used properly.
Click to expand...

we did. ill volunteer to lend the knife to anyone else who has access to a rockwell tester. obviously we are astounded at these results but verified everything was done properly.
BTW the test was performed ~2" from the handle, 1/8" from the spine of the blade b/c that was the flatest spot on the knife.

the knife has no coating

the test was performed in the mechanical engineering lab of a local university and the machine was calibrated before testing.
 
If I had to make a guess I would say it might be a "D" scale reading. You simply can't get 154CM to 74 HRC. The only steels that can approach that are very high alloy ones that have an extreme secondary hardening phase during the tempering.

-Cliff
 
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