HRC Database

[AlexRus]

The DLT Delica OD green DLC cruwear tested at 62.1 HRC.

Good stuff.

Are you getting any readings for the rest of the current K390 Seki series, besides the Delica?

I plan on getting the k390 endura when it is released. I may get the k390 endela as well. I am going to test everything I get now, so I will keep posting them as I get them.

Awesome!

[jpm2]

I wonder if hard coatings like dlc have any affect on the test.

[AlexRus]

I wonder if hard coatings like dlc have any affect on the test.

Sure it does

[Albatross]

I wonder if hard coatings like dlc have any affect on the test.

If you watch jcoolG19 2 on YouTube, he mentions that DLC does alter the HRC test results. I believe he had tested a CPM M4 DLC knife, then sent it back to it's owner, who stripped the coating on part of the blade tang to have it re-tested. The results were different on the second round of testing.

[_centurio_]

Hey everyone,

I just recieved my new GB2 and sharpened it. It sharpened so easily that I had to do a HRC testing at work (we got quite superior equipment ).

2 pokes into the tang, 62,7HRC and 62,3.

I would be a little bit happier if it where a little bit higher, but I think it is good to go.

Maybe it helped you.

BR Oliver

[jpm2]

I wonder if hard coatings like dlc have any affect on the test.

Sure it does

If you watch jcoolG19 2 on YouTube, he mentions that DLC does alter the HRC test results. I believe he had tested a CPM M4 DLC knife, then sent it back to it's owner, who stripped the coating on part of the blade tang to have it re-tested. The results were different on the second round of testing.

If that's the case, how much difference between coated and bare steel?
I assume the coated area tests higher?

[Albatross]

I wonder if hard coatings like dlc have any affect on the test.

Sure it does

If you watch jcoolG19 2 on YouTube, he mentions that DLC does alter the HRC test results. I believe he had tested a CPM M4 DLC knife, then sent it back to it's owner, who stripped the coating on part of the blade tang to have it re-tested. The results were different on the second round of testing.

If that's the case, how much difference between coated and bare steel?
I assume the coated area tests higher?

I can't remember off the top of my head, so I'll try to find the video. I think he mentions a rough estimate of how much DLC changes the reading as well.

[Albatross]

Here's one of jcool testing an ESEE Izula, with it's cerakote and with it's cerakote removed.

https://youtu.be/T9Y4Eas-NoE

I don't recall where exactly in the video he tests the uncoated blades, but this appears to be the video I mentioned.

https://youtu.be/U-jKv3wuXw4

[ZrowsN1s]

If Someone on the Forum wants to update the list, just quote the first post, then go in and add to it. I try to keep the list in order from hardest to softest. You can also see how I format the names. Anyways I haven't had time to work on it in a while, so feel free if you do. I'll update the first post with the new list if you do.

[jpm2]

Here's one of jcool testing an ESEE Izula, with it's cerakote and with it's cerakote removed.
...
I don't recall where exactly in the video he tests the uncoated blades, but this appears to be the video I mentioned.

I would expect soft thick coatings like cerakote to cause lower readings, as was showed in the video. I'm surprised TiN results were the same as uncoated. I would expect ultra hard coatings like TiN and DLC to test harder than bare. Maybe it's because they are so thin. I'd still like to see dlc vs bare on the same knife.

Thanks for the videos.

[Albatross]

Here's one of jcool testing an ESEE Izula, with it's cerakote and with it's cerakote removed.
...
I don't recall where exactly in the video he tests the uncoated blades, but this appears to be the video I mentioned.

I would expect soft thick coatings like cerakote to cause lower readings, as was showed in the video. I'm surprised TiN results were the same as uncoated. I would expect ultra hard coatings like TiN and DLC to test harder than bare. Maybe it's because they are so thin. I'd still like to see dlc vs bare on the same knife.

Thanks for the videos.

No problem. It sure is interesting. I think it speaks to how hard (and possibly wear resistant) some of these coatings are. There is a lot of anecdotal evidence out there, but not much in the way of concrete data.

The second video should have some knives that had already been tested by jcool, but were tested again (in the video) with the DLC coating removed. Did I link the wrong video? I can look again later.

[AlexRus]

Hey everyone,

I just recieved my new GB2 and sharpened it. It sharpened so easily that I had to do a HRC testing at work (we got quite superior equipment ).

2 pokes into the tang, 62,7HRC and 62,3.

I would be a little bit happier if it where a little bit higher, but I think it is good to go.

Maybe it helped you.

BR Oliver

What steel is it?

[_centurio_]

@AlexRus: It is CPM M4

[AlexRus]

@AlexRus: It is CPM M4

Thank you

[Cambertree]

I wonder if hard coatings like dlc have any affect on the test.

The Rockwell C test measures the depth of a conical diamond point penetrating into steel under a fixed load.

The initial load which I guess is intended to ‘break’ the surface is 10kg. This sets the zero position. Then the major load of 150kg is applied then released back to the minor load level.

So any coating would presumably have some effect on the depth of the indentation. Even if the layer of coating is penetrated by the initial load, it will still offer resistance to the edges of the indenter. DLC is very hard - it’s possible that it may even blunt or damage the conical diamond indenter.

Some DLC has apparently been measured at 50% harder than natural diamond.

The hardness and quality of different DLC coatings can vary, and the surface of DLC is not uniform at all, so presumably the same DLC coat could give different readings depending on where the indenter point lands.

The surface of DLC on a micro scale is like cobblestones with gaps between the cobbles, so the point could land in a ‘gap’ or in a spot with varying thicknesses of ‘cobbles’.

I believe this is why there are different reports about the effectiveness of DLC on corrosion resistance. If the coating is ‘dry’ then it may not offer much resistance. But it ‘holds’ oils or protective lubricants or even fats from cutting foods like sausage quite well.

I don’t think you could categorically say that all DLC gives a fixed value over non DLC coated steel. There’s a lot of variables.

[Cambertree]

Hey everyone,

I just recieved my new GB2 and sharpened it. It sharpened so easily that I had to do a HRC testing at work (we got quite superior equipment ).

2 pokes into the tang, 62,7HRC and 62,3.

I would be a little bit happier if it where a little bit higher, but I think it is good to go.

Maybe it helped you.

BR Oliver

Thanks!

Looking at the other results in this thread, your result seems to be squarely in the usual range for the GB models.

I think Spyderco are probably pretty good at hitting that point where there is also a good balance with toughness, given the GB 1 and 2 are ‘hard use’ knives.

I have a GB1 and it has been an excellent performer with a thinly reground edge (9dps with a 15dps microbevel).

Hey, if you have access to a good Rockwell C tester at work, it would be great to see some readings for some of your other Spydies.

[Calicoast]

Been awhile...but still lurking.

Down to a few Spyderco’s.

EDC GB1 which I love.
2 PM2’s:
52100 and one in CTS-204P.
Anyone know what the CTS-204P tested out at?

C

[jpm2]

I wonder if hard coatings like dlc have any affect on the test.

The Rockwell C test measures the depth of a conical diamond point penetrating into steel under a fixed load.

The initial load which I guess is intended to ‘break’ the surface is 10kg. This sets the zero position. Then the major load of 150kg is applied then released back to the minor load level.

So any coating would presumably have some effect on the depth of the indentation. Even if the layer of coating is penetrated by the initial load, it will still offer resistance to the edges of the indenter. DLC is very hard - it’s possible that it may even blunt or damage the conical diamond indenter.

Some DLC has apparently been measured at 50% harder than natural diamond.

The hardness and quality of different DLC coatings can vary, and the surface of DLC is not uniform at all, so presumably the same DLC coat could give different readings depending on where the indenter point lands.

The surface of DLC on a micro scale is like cobblestones with gaps between the cobbles, so the point could land in a ‘gap’ or in a spot with varying thicknesses of ‘cobbles’.

I believe this is why there are different reports about the effectiveness of DLC on corrosion resistance. If the coating is ‘dry’ then it may not offer much resistance. But it ‘holds’ oils or protective lubricants or even fats from cutting foods like sausage quite well.

I don’t think you could categorically say that all DLC gives a fixed value over non DLC coated steel. There’s a lot of variables.

Rather than how much of a difference DLC makes, I was more wondering if the difference would be above, or below the reading of bare steel. But given that the point could land in the gap of DLC coating or not, I guess it could be either way?
Thanks.

[Cambertree]

I wonder if hard coatings like dlc have any affect on the test.

The Rockwell C test measures the depth of a conical diamond point penetrating into steel under a fixed load.

The initial load which I guess is intended to ‘break’ the surface is 10kg. This sets the zero position. Then the major load of 150kg is applied then released back to the minor load level.

So any coating would presumably have some effect on the depth of the indentation. Even if the layer of coating is penetrated by the initial load, it will still offer resistance to the edges of the indenter. DLC is very hard - it’s possible that it may even blunt or damage the conical diamond indenter.

Some DLC has apparently been measured at 50% harder than natural diamond.

The hardness and quality of different DLC coatings can vary, and the surface of DLC is not uniform at all, so presumably the same DLC coat could give different readings depending on where the indenter point lands.

The surface of DLC on a micro scale is like cobblestones with gaps between the cobbles, so the point could land in a ‘gap’ or in a spot with varying thicknesses of ‘cobbles’.

I believe this is why there are different reports about the effectiveness of DLC on corrosion resistance. If the coating is ‘dry’ then it may not offer much resistance. But it ‘holds’ oils or protective lubricants or even fats from cutting foods like sausage quite well.

I don’t think you could categorically say that all DLC gives a fixed value over non DLC coated steel. There’s a lot of variables.

Rather than how much of a difference DLC makes, I was more wondering if the difference would be above, or below the reading of bare steel. But given that the point could land in the gap of DLC coating or not, I guess it could be either way?
Thanks.

I haven’t seen any actual tests, but my guess would be a DLC coated steel would definitely read above an uncoated steel of the same hardness.

Unless the whole diamond cone is punched through the coating with the minor load, you would still think the DLC coat would offer some resistance around the edges.

And then there’s the issue of the indenter possibly being dulled or damaged by the DLC coating too.

I’ve unintentionally stropped a little portion of the DLC off, at the plungeline of my DLC coated 52100 Manix, with diamond abrasives, but that’s the only thing that seems to have affected the coating in any way at all.

It’s extremely hard stuff.

[_centurio_]

Hi,

here are the pics.





BR Oliver