Edge retention carving pine : AUS-6, 10V

[Cliff Stamp]

Similar work, but slicing cardboard :

- http://www.spyderco.com/forumII/viewtop ... =2&t=67337" onclick="window.open(this.href);return false;

Vagabond : 0.021"/12-13 dps
Hunter (Big Chris) 10V-64 HRC : 0.012"/13-14 dps

I was using the Spyderco Fine rod to set the apex bevel ~15 dps. The TSP (termination sharpness point) was set at the point I could not scrape shave. Before I started this semi-seriously I did a quick experiment to see if this was possible to be consistent. I did a run with the Vagabond and three times cut until I determined it could not longer shave and then I measured the sharpness on Espirit Baisting thread and became confident enough that the stopping point was decently defined as I got the following sharpness levels at the end of the three runs :

-16.8 (8)
-15.0 (7)
-15.1 (9)

I did two runs with each knife, the average performance :

Vagabond (AUS-6) :

-Initial edge : 1350 (50) slices
-Reset apex only : 700 (200) slices
-Reset apex again : 300 (50) slices

Hunter (Big Chris) :

-Initial edge : 1000 (50) slices
-Reset apex only : 850 (50) slices
-Reset apex again : 650 (75) slices

The reason that the edge retention tends to decrease is that using just the Fine rod on the apex doesn't remove the fatigued metal so it builds up and the edge retention decreases. At first glance it looks like the Hunter in 10V actually is able to retain a higher consistency of edge retention. However I also changed methods of sharpening after the experience with the Vagabond.

I was doing some reading on fatigue and I wondered if I used a much lighter tough with the Fine rod would this increase the edge retention. Thus with the Hunter I did very light passes and took ~25 pps to get the shaving sharp edge back. I was only doing half of those passes with the Vagabond as I was using more force.

I would want to do more runs to reach anything beyond a weak conclusion, but still it is interesting how strongly different the performance on holding a high polish / push cutting sharpness is very different than the data which comes out from doing a comparison of edge retention on a slice :

- http://www.spyderco.com/forumII/viewtop ... =2&t=67337" onclick="window.open(this.href);return false;

[Cliff Stamp]

A bunch of more results, different steels, all aped bevels were using the Spyderco Fine

Jeremy McCullen SM-100 : full grind / 6 dps edge / 15 dps apex bevel

-Initial edge : 450 (75)
-Apex reset : 400 (50)
-Second apex reset : 300 (50)

Schrade SCH104L 9Cr18 : 0.028"/16-17 dps/20 dps apex bevel

-Initial : 1100 (100)
-Apex reset : 750 (25)
-Second apex reset : 850 (75)

Hunter (Big Chris) 10V-64 HRC : 0.012"/13-14 dps

-Initial edge : 1000 (50)
-Apex reset : 850 (50)
-Second apex reset : 650 (75)

Vagabond : 0.021"/12-13 dps / apex bevel ~15 dps - MXF DMT

-Initial edge : 1350 (50)
-Apex reset : 700 (200)
-Second apex reset : 300 (50)




The interesting thing is that the results are so much more dependent on how the knives are sharpened vs the steel. Especially with the apex resets. With ultra-light force, a light spray of water and a lot of passes the edge retention can be very close to the initial edge, however a bit more force and the edge retention quickly falls to 25-50% which is a bigger difference than any of the blade materials.

[Cliff Stamp]

Update with the Spyderco Pingo

Pingo N690Co: 0.010"/>15 dps/20 dps apex bevel

-Initial edge : 400 (150)
-Apex reset : 450 (25)
-Second apex reset : 750 (75)

Jeremy McCullen SM-100 : full grind / 6 dps edge / 15 dps apex bevel

-Initial edge : 450 (75)
-Apex reset : 400 (50)
-Second apex reset : 300 (50)

Svord 350B 15N20 0.012/12-13 dps / 15 dps apex bevel

-Initial edge : 750 (25)
-Apex reset : 400 (50)
-Second apex reset : 250 (25)

Schrade SCH104L 9Cr18 : 0.028"/16-17 dps/20 dps apex bevel

-Initial : 1100 (100)
-Apex reset : 750 (25)
-Second apex reset : 850 (75)

Hunter (Big Chris) 10V-64 HRC : 0.012"/13-14 dps

-Initial edge : 1000 (50)
-Apex reset : 850 (50)
-Second apex reset : 650 (75)

Vagabond AUS-6 : 0.021"/12-13 dps / apex bevel ~15 dps

-Initial edge : 1350 (50)
-Apex reset : 700 (200)
-Second apex reset : 300 (50)

--

At this point I have realized two runs isn't enough to get consistent results. I have been keeping track of the various pieces of pine and can identify some pieces were are much harder on the edge than others. This difference is easily more than 2:1 . I would want to do at least five runs to have even low confidence in any kind of steel ranking. Note that these are all scrap pine (trim) from the same store, so the variation in wood is likely higher than most expect.

[VashHash]

So what you're saying is a natural material with inconsistency in density would allow inconsistency in your testing..... Ohh do go on. Science is fascinating.....i think you need to find a synthetic pine for a more consistent result.

[Cliff Stamp]

So what you're saying is a natural material with inconsistency in density would allow inconsistency in your testing..

It is a general fact that natural materials have significant random variations in consistency, it would be expected then that this would cause a random spread in edge retention. The question however is the effect going to be larger than the effect trying to be measured. What was of interest to me is that this variation in Pine, even when it is the same type from the same store is indeed larger than the difference in behavior of steels from 10V/64 HRC down to 15N20 and AUS-6 at < 60 HRC .

I knew from past experience this is easily true of cardboard, but with the same type of wood it wasn't expected. What this means is that you could take a knife in M4 and carve some pine and a knife in 420J2 on another piece of pine and the edge retention is higher on the 420J2 because of the difference in the Pine even though they are very similar pieces of the same type of wood.

i think you need to find a synthetic pine for a more consistent result.

That would not be measuring what I want to measure which is the edge retention on Pine.

All I have to do is simply random sample among the Pine and the systematic deviation from one piece to the other will average out. As the runs are large, typically ~1000 cuts, the RMS error will get reduced by a factor of ~30 which will eliminate any systematic bias.

[Cliff Stamp]

Update with the Spyderco K2/Farid



K2/Farid 10V/60+ HRC : 0.020"/9-10 dps/15 dps apex bevel

-Initial edge : 350 (25)
-Apex reset : 300 (50)
-Second apex reset : 350 (25)

Pingo N690Co: 0.010"/>15 dps/20 dps apex bevel

-Initial edge : 400 (150)
-Apex reset : 450 (25)
-Second apex reset : 750 (75)

Jeremy McCullen SM-100 : full grind / 6 dps edge / 15 dps apex bevel

-Initial edge : 450 (75)
-Apex reset : 400 (50)
-Second apex reset : 300 (50)

Svord 350B 15N20 0.012/12-13 dps / 15 dps apex bevel

-Initial edge : 750 (25)
-Apex reset : 400 (50)
-Second apex reset : 250 (25)

Schrade SCH104L 9Cr18 : 0.028"/16-17 dps/20 dps apex bevel

-Initial : 1100 (100)
-Apex reset : 750 (25)
-Second apex reset : 850 (75)

Hunter (Big Chris) 10V-64 HRC : 0.012"/13-14 dps

-Initial edge : 1000 (50)
-Apex reset : 850 (50)
-Second apex reset : 650 (75)

Vagabond AUS-6 : 0.021"/12-13 dps / apex bevel ~15 dps

-Initial edge : 1350 (50)
-Apex reset : 700 (200)
-Second apex reset : 300 (50)

[KevinOubre]

**** cliff, did you modify the handle of the K2 or wear glvoes for that test? I tried doing this type of cutting with the K2 and only got about 100 cuts before my hand was don't from all the hot spots on the handle.

[Cliff Stamp]

cliff, did you modify the handle of the K2 or wear glvoes for that test?

No.

I tried doing this type of cutting with the K2 and only got about 100 cuts before my hand was don't from all the hot spots on the handle.

Yeah, I just ignored that. It gets uncomfortable due to the fact there is a lack of chamfering (lock bar cutout, clip, inside of scales) but I can tolerate it for ~500 slices or so. It is a pretty decent knife in many respects, but it has a few obvious ergonomic flaws. The tip is very specialized as well, but that is part of the ethnic/cultural design. I really keep wobbling on cutting it down though, especially since the last person I loaned it to cut open their hand with an accidental back cut.

[Cliff Stamp]

Update, Chicago :







K2/Farid 10V/60+ HRC : 0.020"/9-10 dps/15 dps apex bevel

-Initial edge : 350 (25)
-Apex reset : 300 (50)
-Second apex reset : 350 (25)

Pingo N690Co: 0.010"/>15 dps/20 dps apex bevel

-Initial edge : 400 (150)
-Apex reset : 450 (25)
-Second apex reset : 750 (75)

Jeremy McCullen SM-100 : full grind / 6 dps edge / 15 dps apex bevel

-Initial edge : 450 (75)
-Apex reset : 400 (50)
-Second apex reset : 300 (50)

Svord 350B 15N20 0.012/12-13 dps / 15 dps apex bevel

-Initial edge : 750 (25)
-Apex reset : 400 (50)
-Second apex reset : 250 (25)

Chigago 440C : 0.015"/13/14 dps/15 dps apex bevel

-Initial edge : 850 (25)
-Apex reset : 800 (50)
-Second apex reset : 550 (25)

Hunter (Big Chris) 10V-64 HRC : 0.012"/13-14 dps

-Initial edge : 1000 (50)
-Apex reset : 850 (50)
-Second apex reset : 650 (75)

Schrade SCH104L 9Cr18 : 0.028"/16-17 dps/20 dps apex bevel

-Initial : 1100 (100)
-Apex reset : 750 (25)
-Second apex reset : 850 (75)

Vagabond AUS-6 : 0.021"/12-13 dps / apex bevel ~15 dps

-Initial edge : 1350 (50)
-Apex reset : 700 (200)
-Second apex reset : 300 (50)

Condensing the list, showing just the performance for worst to best :


-K2/Farid 10V/60+ HRC : 0.020"/9-10 dps/15 dps apex bevel
-Pingo N690Co: 0.010"/>15 dps/20 dps apex bevel
-Jeremy McCullen SM-100 : full grind / 6 dps edge / 15 dps apex bevel
-Svord 350B 15N20 0.012/12-13 dps / 15 dps apex bevel
-Chigago 440C : 0.015"/13/14 dps/15 dps apex bevel
-Hunter (Big Chris) 10V-64 HRC : 0.012"/13-14 dps
-Schrade SCH104L 9Cr18 : 0.028"/16-17 dps/20 dps apex bevel
-Vagabond AUS-6 : 0.021"/12-13 dps / apex bevel ~15 dps

That doesn't show a strong correlation to steel at all which was not expected given I was cutting the same wood from the same store and even of the same type of material (waste trim stock). I didn't random sample the wood as I didn't think it would be needed. I might repeat this at some later point and random sample it. But this experiment confirmed a few points and raised a few questions which is always a good thing.

Video commentary : https://youtu.be/D2vKBuqigBU" onclick="window.open(this.href);return false;

As a closing note, I would really like to see Spyderco put some serious attention to ergonomics. I like the Chicago as it has high utility for its size, but it is full of sharp edges and points on the handle. If someone had a little skill on a buffer and spent 5 minutes chamfering all of the edges on handle liners/slabs it would make a huge difference in use.

[Brunzenstein48]

As a closing note, I would really like to see Spyderco put some serious attention to ergonomics. I like the Chicago as it has high utility for its size, but it is full of sharp edges and points on the handle.

I sign that statement - there are competitors out aplenty focusing rightfully on ergonomics, handling and yes, style as well - and putting not so much focus an less important matters. I (as a laymen) found out that steel quality by far doesn't has that a importance in the real world for the user, the PR focuses at and beats up at the media - but ergonomics certainly has.

[Cliff Stamp]

Indeed. I appreciate many things about Spyderco, the interaction with the customers, the experimenting with new steels, collaborations with custom makers, how they recognize the makers who designed aspects they use (Boye Detent), but I would like to see them give more attention to handles. I have even been given clone/imports which have better ergonomics due to extensive chamfering and that to me just screams wrong if you are inferior in functional regard to a knock-off.

[Galen]

I actually think that one of Spyderco's advantages over other brands is ergonomics. The K2 does seem uncomfortable though I never had it in hand. It is entirely designed after a non Spyderco custom so I wouldn't place it under the same scrutiny as an in house model. The steel used is unnecessary, could have been cheaper and gain other advantages with another steel. Perhaps it was the choice of Mr. Farid, it is what he likes and I respect it.

[Cliff Stamp]

I actually think that one of Spyderco's advantages over other brands is ergonomics.

I would have argued the same, however as of late from what I have seen this isn't as strong a statement for me. However the problem is that we (me anyway) tend to see a small sample of knives and can end up with skewed perspectives. As just one example I recently was given a Bee L01. This is a very inexpensive Chinese import however all edges are rounded/chamfered and aside from the flat clip, it is very ergonomic in hand. This knife is ~$10 but it has a much nicer handle in regards to chamfering than the Chicago and certainly the K2.

The K2 does seem uncomfortable though I never had it in hand. It is entirely designed after a non Spyderco custom so I wouldn't place it under the same scrutiny as an in house model.

I can see that line of argument, but I don't tend to hold it fully. If Spyderco releases it then they have their name on it and I don't think it unreasonable to expect similar performance in all areas. Now there are some knives clearly where aeshetics / visuals are the main point, but still, given the tag-line Sal has of wanting to be the knife in your pocket, I think there is some concern there.

The steel used is unnecessary, could have been cheaper and gain other advantages with another steel. Perhaps it was the choice of Mr. Farid, it is what he likes and I respect it.

I suggested 10V as a knife steel in the 90's on rec.knives and had one of the first customs made in it when Phil Wilson was still working on the heat treatment. Like any knife steel it isn't good or bad, it just has specific properties. If these properties well suit the type of work you do then it will do well, otherwise not. Ideally there would be more discussion of this type, but it will come in time as an understanding of steel deepens.

[tvenuto]

Now there are some knives clearly where aeshetics / visuals are the main point, but still, given the tag-line Sal has of wanting to be the knife in your pocket, I think there is some concern there.

I think it's fair to note, though that often there is a trade-off between pocketability and handle comfort. Anyone who has handled the old D'allara would agree that its handle is supremely comfortable, however the resulting width makes it very hard to carry. I know the main item under discussion is chamfering of corners and removal of sharp edges, which can be done without making the knife wider, but there are always tradeoffs and they aren't always cost related.

[Cliff Stamp]

...but there are always tradeoffs and they aren't always cost related.

I think clarification could be used to distinguish between that which is enhancing one attribute at the detriment of another to just being lacking in an attribute. If an apex comes not well formed and is poor in sharpness then that is a detriment. If the edge angle is 20 dps then that is simply looking at durability of having greater importance over cutting ability (in general). I don't have much of a concern about easy of carry and minimization of thicker grips, that is as you note just assigning one attribute of greater importance and for a lot of people that could be the one which is critical.