Welcome! Log In Create A New Profile

Advanced

Diamond Blades Alpha 1

Posted by CliffStamp 
This forum is currently read only. You can not log in or make any changes. This is a temporary situation.
Diamond Blades Alpha 1
August 03, 2012 12:18AM
Web page : [www.diamondbladeknives.com]

Direct quote :

Quote
Diamond Blades
Alpha 1
Handle : Hand made, hand inleted set of 3 Mosaic Pins for a custom handle.
Steel : Friction Forged® D2 High Carbon Tool Steel
Blade Bevel : 16-18° sharpened bevel
Blade Thickness: 0.100" - 0.105"
Blade Length: 2.750"
Knife Length: 7.000"
Knife Weight: 2.5 oz.
Spine Rc Hardness: 42-44
Blade Rc Hardness: 65-68
Sheath: Vegetable tanned, kydex lined, oiled split grained cowhide
Designer: Charles Allen




A few interesting things :

-the edge is a massive 0.030" thick, this is almost 1/3 of the blade thickness

-the initial sharpness is not impressive, even ignoring the two damaged areas

-it is 80-100 g on the thread in the non-damaged areas, I have seen Spyderco's average as low as 60

-in the damaged areas it is 350+ grams

-it has no slicing aggression at all (the full weight of the blade won't break the skin)

Considering the entire promotion of this is around the steel I expected an edge far greater, but maybe I just got a bad one and this represents the low end of the spectrum.



See the dark line on the edge, that is the dented region there are two. One is about a cm long the other a few mm, the damage is about 1/50 mm deep at maximum - poor QC considering the cost.

Overview :

-aesthetics are high, this is presentation grade
-handle is comfortable, very versatile
-very thick bevel is undesired and expected a deeper primary grind

In short, not a promising start, considering the steel and the promotion of high hardness yet toughness due to an extremely fine aus-grain I expected the edge to be Wilson class, not the same thickness as on the Junglas.
Re: Diamond Blades Alpha 1
August 03, 2012 01:41AM
Wow very disappointing to hear how thick it is behind the edge.
Re: Diamond Blades Alpha 1
August 03, 2012 02:01AM
On an amusing note the first thing I thought was "hey, scandi edge". I actually had to measure it twice as I didn't believe the thickness the first time, 0.030" is heavy even for a chopping knife, it certainly isn't needed for a bird and trout knife. The real interesting thing is that this steel is supposed to have high strength/toughness due to the very fine aus-grind so I expected a very thin edge to take advantage of that.

However there are those that like great big wide bevels, the mora knives of course are the obvious example of this and the main advantage is that there is so much feedback on the bevel against the stone and some people need/want that to make sharpening not an act of frustration. However I don't think sharpening is inherently that difficult that this width of a bevel is needed as a crutch.

The initial damage and low sharpness also is going to be a problem for a lot of people and my concern is for that price there really should be more QA. How about forgetting the presentation packaging and do a bit more careful checking on the knife.
Re: Diamond Blades Alpha 1
August 03, 2012 03:03AM
Tracked down the patent information : [www.google.com]

The work is kind of interesting, and includes chopping into bone, antler, brick and an anvil, and rope cutting . No actual materials data though.
Re: Diamond Blades Alpha 1
August 03, 2012 01:58PM
I got a response from DiamondBlades, they don't consider this acceptable and have offered to replace it. Normally I would not, however as it is an evaluation blade I would like to see the best they can offer with initial sharpness.
Re: Diamond Blades Alpha 1
August 03, 2012 03:01PM
Well this is out, the only sensible way to do it is FedEx completely on their end. They could if they wanted have it picked up, returned and then sent out as a replacement so no fees/duties and they can do everything from their side.

They don't want to do that, they want it returned at my cost, then they will ship the new one, I again pay for any fees/duties, etc. on the next blade and then submit all of the invoices for reimbursement.

I am not that curious to find out how well they can sharpen a knife. Of course to be frank, they have to tread carefully here as if they offered too much then all anyone would have to do was claim the knife came dull and was dented to attempt to leverage something for free.
Re: Diamond Blades Alpha 1
August 03, 2012 03:11PM
That's pretty thick behind the edge at .030".

Will hurt performance a lot so not sure how it would compare to other D2 blades.
Re: Diamond Blades Alpha 1
August 03, 2012 03:20PM
Indeed, I was kind of surprised. I have asked if this is just on this model or is it just how they grind in general. It may have something to do with the actual friction forging in maybe that is as thin as they can forge it and they don't want to surface grind after the forging and risk drawing the hardness. Regardless, that kind of thickness is high even for a chopper assuming quality steel, you really want to be at extremely heavy work to demand that level of thickness, something like being able to shear though knots in oak or similar with very heavy impact splitting. I have also asked around to the guys I know who have one to see if theirs was the same. Bruce had one which he asked Kyley to regrind to full and in retrospect that is a little telling. Kind of strange though, I would have expected the opposite from this given the promotion, i.e., it should be thinner than Dozier's D2, not thicker at the edge.
Re: Diamond Blades Alpha 1
August 03, 2012 04:09PM
If it was in the .015" to .020" it wouldn't be too bad.

I don't even run blades that are in the .030" range....
Re: Diamond Blades Alpha 1
August 03, 2012 04:52PM
A.G. Russell Deer Hunter in D2 is $55.00... just saying.
Re: Diamond Blades Alpha 1
August 03, 2012 08:55PM
The K2 is from 0.010 to 0.020", so it isn't exactly fragile but there would be few who would complain about the cutting ability with an average thickness of 0.015". It is surprising considering how highly the durability and chip resistance is promoted in the patent that they would leave the edge so thick as it indicates the exact opposite property of the steel. I am interested to see what the others guy say who own them as maybe this one just has a really thick edge and it isn't to be expected in general.I have asked DiamondBlade about that as well. But yeah, if you ran this against a Wilson custom in the 0.005-0.010" range on cutting hemp rope in lbs, then the FF D2 would have a heavy disadvantage due to the thickness of the edge.
Re: Diamond Blades Alpha 1
August 04, 2012 10:28PM
I checked with Bruce, his Goddard Hunter from DiamondBlade is the same thickness behind the edge so it seems like it might be the standard spec. No response to an email about it, if it is the standard and if so why.
Re: Diamond Blades Alpha 1
August 10, 2012 12:18AM
Do you plan on sharpening out the damaged areas before testing begins. I saw your initial sharpness video tonight and for a small hunting knife, almost a capping knife, it was not impressive.
Re: Diamond Blades Alpha 1
August 10, 2012 12:27AM
Jim has the knife first, I imagine he will sharpen it before he does any serious work. I would not judge the performance by the knife in this condition as the cutting ability, edge retention/durability, etc. all will be severely biased by the poor initial sharpness and damage.
Re: Diamond Blades Alpha 1
August 10, 2012 06:50AM
Quote
CliffStamp
Jim has the knife first, I imagine he will sharpen it before he does any serious work. I would not judge the performance by the knife in this condition as the cutting ability, edge retention/durability, etc. all will be severely biased by the poor initial sharpness and damage.

Yes I will sharpen it before testing and before I send it on to the next person. spinning smiley sticking its tongue out
Re: Diamond Blades Alpha 1
August 11, 2012 09:16PM
Well, I am curious to see results here....Oh wow I am an idiot, I read the knife length as the blade length and was utterly shocked by how tiny it looked...Yeah.

On a more serious note, I am struggling to figure out why a knife not even 3 inches needs to have that thick of an edge and why it is thought that the edge will perform properly ( I mean for $350, that's kind of ridiculous as I would expect something like that in a cheaper blade rather than a high end knife.) Or perhaps this is expected to be more of a display knife?
Re: Diamond Blades Alpha 1
August 11, 2012 10:06PM
Quote
Agith
I am struggling to figure out why a knife not even 3 inches needs to have that thick of an edge

It doesn't.

Quote
Agith
and why it is thought that the edge will perform properly ( I mean for $350, that's kind of ridiculous as I would expect something like that in a cheaper blade rather than a high end knife.)

Some people have more money then brains, expectations, experience or practical necessity and won't reach this conclusion.

Quote
Agith
Or perhaps this is expected to be more of a display knife?

Its not pretty enough to be honest.
Re: Diamond Blades Alpha 1
August 11, 2012 11:40PM
Quote
Agith
I am struggling to figure out why a knife not even 3 inches needs to have that thick of an edge and why it is thought that the edge will perform properly

I asked DiamondBlade, no response from the President of the company in email. The thing I find interesting is that they have a number of custom makers involved in the design so it is odd that no one mentioned that generally hunting/caping/bird&trout knives are much slimmer at the edge. Also curious is that for knives of that price point they seem to set all of the edges the same as Bruce doesn't have the same one I have and the edge is the same thickness. I am curious with all the R&D that they seemed to advocate did no one actually ever just take one and use it alongside a 0.010" Deerhunter from A. G. Russel and not see the large difference in cutting ability and ease of sharpening?
Re: Diamond Blades Alpha 1
August 12, 2012 02:32AM
All I know is I won't be buying from them, for that price I'll buy a busse which not only do I know will perform ( Within the bounds of its design ) but that warranty is incredible. Well, I suppose if you want to go chopping down trees...Err not that's not gonna happen with this knife, I'll keep my victorinox ranger for EDC ( Thus far it's performing very well, though I had to buy a sheath for it since it's so awkward in the pocket.) granted I still carry my 0350 as an EDC knife ( Two knives on my person seems to have become the norm. )
Re: Diamond Blades Alpha 1
August 12, 2012 07:36AM
sorry i can not get the Phorum to copy the graphs, but you get the idea from their "white paper" here:

http://www.diamondbladeknives.com/images/userfiles/file/20110429100535_6_FFTechdocument.doc

PERFORMANCE TESTS RESULTS

Over 600 individual tests were conducted comparing Friction Forged® blades against the exact same blade style but made up of 12 different steels. These other tests steels were 1095, BG42, AISI 01, AISI A2, 5160, 52100, 154CM, 440C, D2, CPMS90V, CPMS30, and Talonite. It is far beyond the scope of this introduction to Friction Forging® to report all these results. We will however, show results comparing Friction Forged® blades to “best processed” D2, CPM90V and CPMS30 as the S90 and S30 were the steels that came the closest to Friction Forged blade performance. The D2 steel was selected to show the dramatic performance increase in that steel due to Friction Forging®. The D2, S90 and S30 all had HRc values between 59-61 and all had cryogenic “deep freeze” treatments.

GRAPHS

The following graphs demonstrate the superiority of the Friction Forged® blades compared to other traditionally processed steels. Figure 1 shows that the Friction Forged® blade starts out sharper, cutting 50% more material per stroke at the outset. But not only does it starts out sharper, it stays sharp longer. After cutting through 250 inches of rope, the blade is still cutting more than 0.2 inches per stroke. The next best material, S90V, was reduced to cutting only 0.2 inches per stroke at about 75 inches of total media cut. By 125 inches total media cut, the S90V was cutting only about 0.15 inches per stroke. Clearly the Friction Forged blade keeps its sharp edge longer.



Figure 1: ERT Sharpness (inches of rope cut per stroke) as a function of the total media cut.



In Figure 2, we see how much rope can be cut without losing shaving sharpness. A series of tests were performed that showed knives with an ERT value of 3 would no longer shave, while knives with a lower value would. Accordingly, the ERT test was run until the REST value was greater than 3. Ordinary D2 loses its shaving ability at about 10 inches of rope cut. S30V makes it to 100. S90V lasts until about 140. But the Friction Forged D2 still had a REST value less than 3.0 with more than 250 inches of rope cut.


Figure 2: Total media cut as a function cumulative REST sharpness

Figure 3 illustrates the number of strokes it takes to dull the blade. As discussed previously, the objective is to keep the REST value under 3.0. Ordinary D2 lasts for about 15 strokes. S30V makes it to about 360. S90V goes to about 799 strokes. But even after 1000 strokes, the Friction Forged D2 blade is still well under 3.0.


Figure 3: ERT sharpness as a function of the number of strokes cut in the ERT media

The performance in the tests as shown above clearly shows that the Friction Forged® D2 blade cuts more material at lower forces for more strokes than any of the competitors.


IN SUMMARY
1. Friction Forging® is a proven technological leap ahead of any other manufactured knife blade. The grain structures are extremely fine “nanosized” at less than 0.5 microns and thus allow a super hard, tough edge that will hold a “shaving sharp edge” longer than any other knife blade material tested under strict laboratory conditions.
2. Friction Forging® plasticizes the forged area and Chromium carbides return to solution. The rapid edge quench freezes some of the Chromium into the ferrite before it can be combined again with carbides and actually creates a true stainless steel processed edge zone in D2. This prevents edge degradation due to corrosion.
3. Friction Forging® allows the manufacture of a differentially hardened blade as the Friction Forged® zone is a narrow ½ inch wide zone along the knife-edge with HRc values between 65 and 68. The area immediately above the Friction Forged® zone is in the mid 50’s HRc and the remainder of the blade is engineered to have a lower HRc value of 45 thus providing a tough, slightly “springy” blade that resists breakage under extreme conditions.
Re: Diamond Blades Alpha 1
August 12, 2012 02:10PM
This is imo the most important part of their entire shitck.
Quote

2. SAME GEOMETRY: When testing, test blades must be of the EXACT same edge and overall geometry. All test blades were ground on an American Siepmann VG3 grinder to a .020 edge thickness.
Re: Diamond Blades Alpha 1
August 12, 2012 03:37PM
Thanks for putting up that link, I had meant to post up that before. Here is the full pdf : [www.cliffstamp.com] .

Here is some commentary I made on these results when they were first posted :


Figure 1:

Look at the CHANGE in peformance. The S90V blade degrades by 0.1, the FF D2 blade changes by 0.2. Thus the FF blade degrades TWICE as much as the S90V blade.

Figure 2 and 3:

The entire superiority hinges on one point in the S90V blade which is lower. But the variation in the performance of the blades due to measurement uncertainty is WAY HIGHER and this small change is not significant.

In short, the information provided raises some interesting questions such as why was the FF D2 blade so much sharper initially (wrong abrasives used I would assume). But give no clear evidence of edge retention increase and in fact show it to be inferior in rate of degredation to S90V by 2:1.

This is why I have said many times that what you do has no bearing on if something is "scientific" or not, but how the data in interpreted and what conclusions are drawn. This is an example of a lot of precise numbers which are not utilized properly and the conclusions presented are not rigerously supported by the analysis.
Re: Diamond Blades Alpha 1
August 12, 2012 04:22PM
Thank-you for those graphs...But as for the superiority complex they have going, my problem with that is don't various steels have different ideal methods of heat treating? Meaning that they went with what was best for their steel, yet left the others knowingly to receive such a treatment ( Perhaps I am wrong in that regard? )

It's interesting how they believe the differential treatment to be ideal in the first place, as all blades wear down and as they are used, the edge moves closer to the spine, making that "special" heat treat only temporary.
Re: Diamond Blades Alpha 1
August 12, 2012 06:10PM
Yes, all this is really an example of “jumping in the deep end of the pool”. After having delved for the last 6 months (admittedly on a very amateur and back-yard hobby level) into that pool, I have the following observations to make on the DB ‘testing’. ( I probably could make a lot more than this, but I think just a few will give you the gist of it )

I dismiss, out of hand, all CATRA abrasive pad testing results, whether they are testing DB blades or razor blades. I put no credibility in a testing machine that tries to make numeric factual statements about testing cutting ability in a contrived media. I have been very critical of the CATRA abrasive media tester for a long time. This is not so much a knock on the CATRA design, but a knock on the whole concept of making an instrument that you think can give results from a blade/single type media system. If you have a blade/abrasive degradation testing regime the two pieces of the puzzle become an unwind able helix of interactions during the test that is particular to the given media in use at the time. Change the media and the result become wildly different across several blades. One tests results, it seems, can never be related to any other test. Going through a series of even slightly different ‘media’ will give hugely different profile slope results of even the same blade. I can tell you that after testing many different possible media candidates for my simple back yard sharpness tester jig that I finally just ‘gave up’ trying to land on a definitive cutting ability media that I could say really “works” across a platform of more than two or three random sample blades. However, on the other hand, the type of test that CATRA calls the Razor Edge Sharpness Tester, has some has merit.

This is the type of test I finally wound up doing on my own machines as I believe the results do have some meaning, if properly conducted. However, that is where the DB “white paper” is having issues. I will just site two examples where they ‘spinning the results); In Figure 2: Total media cut as a function cumulative REST sharpness, they have ‘discontinued the test after the REST values exceed 3. That is exactly *not* what you want to do! You want to extend the number of trials well beyond that to get at the slope profile that will be revealed only after continuing the test! By picking an arbitrary point to ‘discontinue’ then it leaves open then question of ‘chart fiddling’, it then looks like someone looked at a chart that contained all 500 cuts for each series and said, :lookie-here if we just slide the cut off point of the REST back to three then no one can see that the s90V sloped off to flat and after settling in at RST 3.5 it retains excellent sharpness of the next 500cuts” (or whatever it might have showed, who knows exactly what was revealed, but for sure to present the data the way they did reveals clear “fiddling”)

In chart #1 Cliff has already noted the issues. It is the slope you care about not the initial sharpness point, but since the DB blade was started the test series as ‘sharper’ in the first place it causes the series line for the DB blade to appear to “float above” the rest of the series lines, and to the untrained eye, this “looks better” .

Hummm.. Oh well, I still would like to have a look at one of these knives. I wish them the best of luck in the marketplace. After all, everyone has to start somewhere. Maybe the future ahead for them is bright,



Edited 1 time(s). Last edit at 08/12/2012 06:11PM by BassLakeDan.
Re: Diamond Blades Alpha 1
August 12, 2012 09:19PM
Quote
BassLakeDan
One tests results, it seems, can never be related to any other test. Going through a series of even slightly different ‘media’ will give hugely different profile slope results of even the same blade.

The CATRA machine is designed to look at wear failure as that is the dominate mode of failure for most blades as most people tend to take knives to extreme levels of dulling, and in industry the same it true. The curious thing is that I have not seen anyone answer the question as to does the CATRA machine actually give you something beyond a simple abrasion test as it seems like every promoted knife steel just ends up ranked based on abrasive wear. If you look especially at the CPM data sheets this is extremely clear.


Quote

That is exactly *not* what you want to do! You want to extend the number of trials well beyond that to get at the slope profile that will be revealed only after continuing the test! By picking an arbitrary point to ‘discontinue’ then it leaves open then question of ‘chart fiddling’, it then looks like someone looked at a chart that contained all 500 cuts for each series and said, :lookie-here if we just slide the cut off point of the REST back to three then no one can see that the s90V sloped off to flat and after settling in at RST 3.5 it retains excellent sharpness of the next 500cuts” (or whatever it might have showed, who knows exactly what was revealed, but for sure to present the data the way they did reveals clear “fiddling”)

Yes, exactly right. Look at the S30V blade, it was stopped because of ONE point, but the points before it show high scatter, so that one point could have just been high scatter and the next point could have dropped down and the cutting stabilized like you said. But obviously this is promotional data from the manufacturer, you have to expect all statistics will be heavily biased. The curious thing to me is how little these results, which are obviously heavily biased (in interpretation/analysis) were so readily accepted when they were presented yet even high school lab work would never allow such a thing to pass.

Quote
Agith
But as for the superiority complex they have going, my problem with that is don't various steels have different ideal methods of heat treating? Meaning that they went with what was best for their steel, yet left the others knowingly to receive such a treatment ( Perhaps I am wrong in that regard? )

It's interesting how they believe the differential treatment to be ideal in the first place, as all blades wear down and as they are used, the edge moves closer to the spine, making that "special" heat treat only temporary.

Yes, all steels would have heat treatments optomized for the use, without saying how they were hardened it is impossible to know how representative the blades are of what could be achieved. Perhaps the regular D2 performed so poorly as it was not cold quenched and was left with high levels of retained austenite?

While it is true that only a small amount of the edge is friction forged, I don't think that is a practical concern as knives of this class (cost) tend to be very lightly used. When is the last time you say a picture of any knife with 1/4" worn off of the edge for example? It would be an interesting question though as to what they would do if that happened.
me2
Re: Diamond Blades Alpha 1
August 12, 2012 11:22PM
Quote
CliffStamp
The CATRA machine is designed to look at wear failure as that is the dominate mode of failure for most blades as most people tend to take knives to extreme levels of dulling, and in industry the same it true. The curious thing is that I have not seen anyone answer the question as to does the CATRA machine actually give you something beyond a simple abrasion test as it seems like every promoted knife steel just ends up ranked based on abrasive wear. If you look especially at the CPM data sheets this is extremely clear.

Interesting, as that is the opposite of what I've just posted on another forum. Loss of sharpness is dominated by edge rolling/deformation. However, I did not qualify that statement with my personal preferences for high sharpness, arm shaving and up.
Re: Diamond Blades Alpha 1
August 12, 2012 11:40PM
Quote
me2


Interesting, as that is the opposite of what I've just posted on another forum.

CATRA goes to extreme levels of blunting :



These are actual CATRA result for a very simple steel, note towards the end the sharpness is 1-2% of optimal. I have never ran a blade that blunt unless I was cutting something like carpet or shingles, on rope/cardboard it would take forever, even with something like AISI 420.

In general it would be of benefit to talk about how sharp the knives are going to be before resharpened before discussing edge retention, but it is hard enough to get people to differentiate between cutting ability and sharpness to make this small refinement.
Re: Diamond Blades Alpha 1
August 14, 2012 06:22PM
Quote
Agith
It's interesting how they believe the differential treatment to be ideal in the first place, as all blades wear down and as they are used, the edge moves closer to the spine, making that "special" heat treat only temporary.
Quote
CliffStamp
While it is true that only a small amount of the edge is friction forged, I don't think that is a practical concern as knives of this class (cost) tend to be very lightly used. When is the last time you say a picture of any knife with 1/4" worn off of the edge for example? It would be an interesting question though as to what they would do if that happened.
I've seen many an older Buck, Kabar, Barlow, and SAK with >1/4" of the edge worn/sharpened away.
I would presume, however, that those blades had lower edge-hardness and abrasion resistance, dulling more quickly and so requiring more maintenance. Also these knives have often reached >30 years of service. If the DB knife lasts 2x that lifespan, more power to it, but I know that I'd feel strange dedicating such an expensive knife with so much material left to butter & creamcheese ...
Re: Diamond Blades Alpha 1
August 14, 2012 06:47PM
It actually isn't impossible for them to reharden it in that instance. I emailed them about that and do not have a response. Note that this isn't a concern just of DiamondBlades, lot of people who forge and edge quench often leave the very hardened edge very shallow and only the very edge itself is the full cutting hardness. I have not seen a lot of practical problems with that - but, these knives are often extremely expensive.
Re: Diamond Blades Alpha 1
August 30, 2012 02:36AM
As a fairly curious point of comparison to show how ridiculous the edge bevel thickness is on this knife. The Hoodlum warranty replacement has the following edge profile :

0.035-0.040"/16-18 dps

This is extremely close to this small Bird/Trout knife.