Benchmade 3v

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skyhorse said:
I'd really like to know how a blade coating brings down the rockwell rating on heat treated blade steel ?
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It’s hard to describe without showing the whole testing process but basically the indented has to travel through the coating and the steel, which gives a longer travel distance and a lower measured HRC. Rockwell tests measure hardness indirectly by directly measuring how far a specifically shaped indented travels into a test specimen.
 
Curious how an Internet forum seems to attempt a redesign and re-engineer a model, based on what, exactly?
 
skyhorse said:
I'd really like to know how a blade coating brings down the rockwell rating on heat treated blade steel ?
Click to expand...

Surface preparation-related causes

Rough surfaces cause rough results. If you’re only interested in knowing roughly how hard a part is, a rough surface will work. But if you’re inter- ested in accurate, consistent test re- sults, always test a shiny surface. Even though the Rockwell method begins its hardness measurement beneath the surface of the part, the inherent vari- ability of a rough surface can and will cause inconsistent results.

Surface coatings or hardened layers also can provide deceptive results. If you want to test the hardness of a coating or surface layer, use a load/indenter combination that will ensure that the measurement is taken in the coating or layer. Remember the 10X rule: the thickness of a part or coating must be 10X greater than the maximum depth of penetration. On the other hand, if you are interested only in the hardness of the substrate and not that of the coating, the coating or surface layer must be removed using a suitable surface preparation technique.
https://www.asminternational.org/do...416b-8f06-4ac5-8511-244aa5fc54c0/HTP00403P023
 
dano said:
Curious how an Internet forum seems to attempt a redesign and re-engineer a model, based on what, exactly?
Click to expand...

I didn’t bring this over here. I simply posed a scenario that @Benchmade still refuses to answer and I do say refuse. I have a screenshot where whoever is in charge of their account admits that they’re aware of this conversation and they’re going to respond, but that was hours ago. Interesting isn’t it...hmmmm
 
Alchemy1 said:
I didn’t bring this over here. I simply posed a scenario that @Benchmade still refuses to answer and I do say refuse. I have a screenshot where whoever is in charge of their account admits that they’re aware of this conversation and they’re going to respond, but that was hours ago. Interesting isn’t it...hmmmm
Click to expand...

I doubt their social media person is an engineer, or was even involved with the design. It actually makes me feel better that they're (hopefully) taking the time to get a proper answer from someone with design and metallurgy knowledge, rather than just telling you "that's the way it is" and dismissing your evidence.

If they don't answer you soon, that might be more of a problem.
 
Silent H said:
I doubt their social media person is an engineer, or was even involved with the design. It actually makes me feel better that they're (hopefully) taking the time to get a proper answer from someone with design and metallurgy knowledge, rather than just telling you "that's the way it is" and dismissing your evidence.

If they don't answer you soon, that might be more of a problem.
Click to expand...

Anybody that knows business or customer service knows that you at least keep the person busy while you figure out a solution. Even if you just say, “wait here while I get my boss”. The message also literally says that THAT person is about to comment. We need to stop making excuses for companies. It’s sad and only hurts us, the consumer.
 
Silent H said:
I doubt their social media person is an engineer, or was even involved with the design. It actually makes me feel better that they're (hopefully) taking the time to get a proper answer from someone with design and metallurgy knowledge, rather than just telling you "that's the way it is" and dismissing your evidence.

If they don't answer you soon, that might be more of a problem.
Click to expand...
They probably got to wait for Stacked to get back to them.

Here's some science lol
 
skyhorse said:
I'd really like to know how a blade coating brings down the rockwell rating on heat treated blade steel ?
Click to expand...
As noted above, hardness testing works by measuring the depth of a dent made in the material when pressed upon with a specific tool with a calibrated force. If you put cerakote on something, which can be .001"-.002" thick (cerakote is extremely thick for a coating), then you would get an inflated depth of indentation, which would indicate a lower hardness. The depth of deformation is already extremely minimal, so this makes a noticable difference. This wouldn't matter so much if the coating was DLC (which is substantially thinner), but since cerakote is so thick it probably threw the values off.
 
I've been sharing in the Instagram discussion.

dxjJRNA.png


This is how the test works. The red feature in the picture is a 120° diamond conical penetrator. It is first set at the minor load with 10kp or Kiliograms of force shown as "F1" than given the the major load "F2" 140kp and held for a moment before releasing back to 10kp. The permanent deformity in depth is measured as "e" in mm gives you the Rockwell hardness test scale c.


This is the formula

OtX68BQ.png



The dial of the machine goes to 100 HRC and is subtracted from the mm of permanent deformity "e" over 0.002mm which is increments of measurement used by the instrument.

So let's say that the Benchmade is within the advertised 57-59 rc at 57.5rc.

That would be 0.085mm of permanent deformity for 57.5 HRC

0.085÷0.002
= 42.5
100-42.5
=57.5HRC

Now if the cerakote is 0.001" thick that would be 0.0254mm

Given the hardness of cerakote, it may not be affected the 10kg of force from the preload but would most definitely be smushed by the 140kg of force from the main load.

That would add additional depth to the permanent deformity measurement in mm.

0.0254mm + 0.085mm
=0.08754mm
0.08754÷0.002mm
=43.67
100-43.77
=56.23HRC
 
marrenmiller said:
As noted above, hardness testing works by measuring the depth of a dent made in the material when pressed upon with a specific tool with a calibrated force. If you put cerakote on something, which can be .001"-.002" thick (cerakote is extremely thick for a coating), then you would get an inflated depth of indentation, which would indicate a lower hardness. The depth of deformation is already extremely minimal, so this makes a noticable difference. This wouldn't matter so much if the coating was DLC (which is substantially thinner), but since cerakote is so thick it probably threw the values off.
Click to expand...
I would think a rockwell test would be done before any blade coating was applied ?
 
Twindog said:
Surface preparation-related causes

Rough surfaces cause rough results. If you’re only interested in knowing roughly how hard a part is, a rough surface will work. But if you’re inter- ested in accurate, consistent test re- sults, always test a shiny surface. Even though the Rockwell method begins its hardness measurement beneath the surface of the part, the inherent vari- ability of a rough surface can and will cause inconsistent results.

Surface coatings or hardened layers also can provide deceptive results. If you want to test the hardness of a coating or surface layer, use a load/indenter combination that will ensure that the measurement is taken in the coating or layer. Remember the 10X rule: the thickness of a part or coating must be 10X greater than the maximum depth of penetration. On the other hand, if you are interested only in the hardness of the substrate and not that of the coating, the coating or surface layer must be removed using a suitable surface preparation technique.
https://www.asminternational.org/do...416b-8f06-4ac5-8511-244aa5fc54c0/HTP00403P023
Click to expand...
I've always assumed testing was done on blades prior to any coating process ?
 
H0kieengineer said:
It’s hard to describe without showing the whole testing process but basically the indented has to travel through the coating and the steel, which gives a longer travel distance and a lower measured HRC. Rockwell tests measure hardness indirectly by directly measuring how far a specifically shaped indented travels into a test specimen.
Click to expand...
The HRC testing is normally done before finishing process such as blade coatings at Buck and I don't think a coating would affect the hardness of the metal it's applied to.
 
DeadboxHero said:
You're missing the point here.
The Benchmade was hardness tested by another person. Not Benchmade.
Click to expand...
My point is a blade coating shouldn't affect the hardness of unlaying steel. If Benchmade does a lousy job on their heat treat the coating won't change that.
 
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