- Joined
- Jan 15, 2015
- Messages
- 446
You will need to put the yoke upside down on your scale and cut the thread freehand.
-
The BladeForums.com 2024 Traditional Knife is ready to order! See this thread for details: https://www.bladeforums.com/threads/bladeforums-2024-traditional-knife.2003187/
Price is$300$250 ea (shipped within CONUS). If you live outside the US, I will contact you after your order for extra shipping charges.
Order here: https://www.bladeforums.com/help/2024-traditional/ - Order as many as you like, we have plenty.
Edge Sharpness Tester
- Thread starter rlucius
- Start date
You will need to put the yoke upside down on your scale and cut the thread freehand.
- Joined
- Jun 4, 2010
- Messages
- 6,642
Josh, I've had several knives come out with higher or stagnant BESS values when run through a progression - even while slowly performing better on other cut tests like paper towel, fine newsprint, hair. I have no explanation but speculation that the BESS line is testing for qualities which are somewhat specific, but perhaps not necessarily specific to a particular edge finish past a certain point.
As with the other test you posted, the numbers began to waver and drop a bit when you begin using films and stropping compound. There may be a trend or maybe not....
What steel was the Gayle Bradley? I've been trying to keep up on the type and if known, RC of the knives I've been testing.
Martin
- Joined
- Jun 13, 2007
- Messages
- 7,743
Just got mine, yay! Haven't even taken it out of the box, but I have a question for the other testers...
Will you be taking EOU up on their generous offer? To me that speaks to how useful you might find the tool in general.
Will you be taking EOU up on their generous offer? To me that speaks to how useful you might find the tool in general.
Okay just clarifying.
Well, I'm not really sure that we should expect a linear increase in sharpness when it comes to the increase in an edge's ability to shave/whittle/manipulate hair in some way. I've noticed even before using this machine that an edge that could do the hair-hanging tests, felt a little less biting to the touch than one that could just whittle hair. I think others have noticed this in the past when arguments of coarseness vs fineness come up...
Then there's the issue with hair being such a non-standard medium in the first place, that is what begets this machine having a fundamental purpose. Honestly I can get knives that only read 150 BESS to whittle hair if I sit and finagle the hair around enough to get them to catch, but is that the same as one that just peels strands off a free-hanging hair with no deflection, or one that passes a hair-hanging test? Not really sure there can be a direct comparison to be made.
For one reason, the media itself... Hair is non-standard, already covered that, but the characteristics I'm guessing are not like that of the BESS media. We know hair gets narrow from the base towards the tip, and that it has little "scales" that the edge can ride up under, whereas I'm guessing the BESS media is just on uniform mono-filament. Beyond that, the way the cut is made into hair--even in hair-hanging tests--often tends to kind of go along with the hair and start splitting it parallel.
It could also be that the test media is biased toward coarser finishes with "toothier" serrations that are creating pressure points and causing the media to splay and severe faster than a more polished edge is?
Ankerson
Knife and Computer Geek
- Joined
- Nov 2, 2002
- Messages
- 21,094
Nope....
Manix 2 CPM S110V, 15 DPS, .005" behind the edge at 1 Micron polished edge on EP, Just a quick one, maybe 10 mins of work going from 400 grit to 1 Micron.
28, 27, 28 = 27.7 ave.
Just did a quick one to see, don't bother with polished edges anymore personally, but I still have all the gear so I said what the hell I will do a quick one.
So I am in the mid 40's at 400 grit or 40 Micron and the high 20's at 1 Micron, I don't see the point personally of going any higher than my 400 grit stone (40 Micron) on knives, sharp is sharp, anything under 50 BESS is insane anyway.
Last edited:
- Joined
- Jun 4, 2010
- Messages
- 6,642
Kenny, so far I haven't noticed a hard and fast trend that is 100% predictive. The same edge prep on the same steel type at the same apex angle seems to produce very comparable numbers. Changing any variables such as steel type and keeping the edge prep the same will produce different numbers, as will changing the prep and using comparable steel types, etc.
Looking at my results so far, I am amazed my wife's kitchen knife rang in under 200 with an XXC DMT and smooth steeling finish. The edge is visibly non-uniform, though due to being steeled is very thin across the edge - far less variation than straight off the plate, and has regions that have been burnished free of fine scratch marks. It is still extremely toothy but variation in width across the cutting edge is very small and the inclusive is under 30.
The better numbers do come from the higher polish, in combination with a relatively thin apex angle. I have yet to pull good numbers from anything with inclusive apex much over 30 - though I'm sure it can be done, will likely require ever increasing levels of polish and angle holding. If the inclusive were to creep much into the mid to upper 30s as a result of the finishing process, you'll be going uphill fast.
As mentioned, some cut tests do not jibe with the BESS cord results. I can hear the pitch of some edges going through hanging newsprint increase to higher frequencies and make less noise, yet the BESS number might not budge more than the margin of error (10-20). It could be the BESS cord is revealing some induced freehand defect - even as the edge becomes more refined it is becoming more broad? In some cases the BESS number does drop in conjunction with other cut test improvements, and in some cases the BESS number has gone down while other impromptu tests showed no real gain.
The BESS cord is a single type of media, and edges that have the best characteristics to sever it might not perform as well on other media, nor should we expect them to. For me there are two questions - does the BESS standard provide more solid, comparative, usable data for determining what is sharp compared to other tests, and if so and if possible to narrow it down, what exactly is the BESS cord testing.
- Joined
- Jan 27, 2013
- Messages
- 2,078
- Joined
- Apr 1, 2014
- Messages
- 868
This has turned out to be a fascinating thread! Thanks to all the testers for sharing all of this information - you guys rock. And thanks to the OP and EdgeOnUp!
I am most impressed with how the company sent you guys these instruments and then just stood back and watched. If the product is good, it will speak for itself!
Really cool to see a new standard coming to life.
Eric
I am most impressed with how the company sent you guys these instruments and then just stood back and watched. If the product is good, it will speak for itself!
Really cool to see a new standard coming to life.
Eric
- Joined
- Jun 4, 2010
- Messages
- 6,642
The highest polish I've used has been my stock WB compound, 6k at best. I haven't tried any of my finer stones on it but will have to give it a go!
- Joined
- Jan 15, 2015
- Messages
- 446
The bevel angle near (a few microns from) the apex is about 25 degrees (inclusive) on an Astra. The thickness of the blade is only of consequence to the depth of penetration prior to cleaving. I wonder how far the blade penetrates before the media cleaves.
I made some quick measurements cutting sewing thread on a kitchen scale; Astra 10-12g, Feather Super Pro 5-6g, the straight razor I shaved with this morning 3g.
The absolute measurements are of little consequence; I only provide these as evidence that there are keener blades than an Astra DE. In other words, Jason's experience is not surprising to me.
The concern I have with the BESS media is that the pressure (force/area) seems rather high. For example, 100g applied to a 0.009 inch filament produces equivalent pressure to 10lbs force on a 3/8inch poly rope (41x). The obvious question is whether highly refined, low angle edges are being folded or blunted by the test - and therefore scoring lower (higher weight). This could also suggest that free-hand, convex blades with their higher near-apex angle will test more reliably.
Yeah leave it to the guy who scored a 9 with a DMT F hone to not understand
I haven't tried stropping to see how that effects my results, I'm still working on getting BESS numbers under 100 so I can reliably measure them with my scale. I may have to borrow my friend's or something to do more thorough testing without having to get my knives all sharp first, and it'd be great to test edge degradation or just not have to have a sub-100 knife.
ToddS, that is an interesting point about pressure... I'm wondering if that's why my Izula has scored the best so far. Normally Izulas have a pretty obtuse edge but I re-profiled mine quite a bit, hell I shave with it now. But the thickness of the blade stock is still significantly higher than the other knives I tested so I just didn't expect it to get sub 50 numbers at all.
I got my SAK knife ( also a 20 degree back bevel with a 30 degree micro ) to about 70 last night, but then somewhere along the line erased my progress and got back up to just under 100. The Leek just won't go under 80, I figure unless I reprofile the edge again and really why bother--it seems that 50-100 is pretty darn sharp and all I'm gonna do is ruin my edge retention.
My Wild Turkey was the most disappointing. I really thought I'd be able to get it sharpest of all of them but it's actually the most disappointing. Could only get it down to about 92 on the BESS.
So... All finished on a DMT F continuous hone.
Stainless Izula ( 440C ), 20 degree back bevel and 30 degree micro, .035" behind edge:
46.3
14C28N Leek, 36 degrees and .025" behind edge:
81
Kershaw "Wild Turkey" VG-1, 20 degree back bevel with 30 degree micro, .020" behind edge:
92
SAK "Super Tinker" main clip blade... 20 degree back bevel with 30 degree micro, .015" behind edge:
71
What I really like about this device is it takes out the guess work. If I've been honing a knife for a bit I'll test on my finger-tips and go, "Hmm, that feels like it might be sharper," but with the tester I could go test it and literally SEE a 10-15 point decrease. Then on top of that if I think, "Wait did I roll over the apex and dull the edge on those passes?" you can test that too, so there's not a lot of "guessing" about what you're doing anymore and I think that's going to break down the learning curve for each particular knife edge much faster. I do kind of wonder if I got my Izula sharper because I'm more use to sharpening it than any other ( I do sharpen it to be able to shave my face every week after all ) and having got the SAK so close to below 70 I think the device can definitely show the person where its their limitations holding them back and not their equipment when sometimes that line is a little blurry.
Oh, and I was curious what point on the BESS scale others were reaching "hair whittling" and "hair shaving". I've often been curious if some people's hair whittlers are sharper than others. I haven't really been able to play on very high ends of the scale over 200 grams so...
200 - Will uncomfortably cut hair off arm
150 - Will shave arm hair comfortably, barely whittle hair with some finagling
100 - Will pop arm hair off, whittle a free-hanging hair readily into multiple strands
50 - Will cleanly sever the hanging hair in an instant if slice isn't at right angle
Hey does anyone have an ESEE 3 to test? Unfortunately mine is in pawn.
Last edited:
Jason B.
Knifemaker / Craftsman / Service Provider
- Joined
- Jun 13, 2007
- Messages
- 11,168
I have experienced NO edge damage in my testing, though I can't say it has not crossed my mind given the tension and sometimes aggressive snap of the test media.
I have also been getting the feeling this device is limited to a smaller range of sharpness than I commonly deal with. Most Yanagi, Deba, or Usuba would not even read on the testing unit because their sharpness would be on a level beyond the BESS scale and the test units capability. Same with Straight Razors or very thin knives with thin edge angles and high polish. As we all know, different edge finishes will "play" differently with the objects to be cut and I think we are seeing some of that here in the test media.
I am a little skeptical you could say because I get 20-40 gram readings on knives with 2000 grit waterstone edges, this is not even close to the level of sharpness a shaving razor needs to be. I've also had as low as 5 grams on 600 grit edges and 32 grams on machine edges (120 grit and polish).
I have also been getting the feeling this device is limited to a smaller range of sharpness than I commonly deal with. Most Yanagi, Deba, or Usuba would not even read on the testing unit because their sharpness would be on a level beyond the BESS scale and the test units capability. Same with Straight Razors or very thin knives with thin edge angles and high polish. As we all know, different edge finishes will "play" differently with the objects to be cut and I think we are seeing some of that here in the test media.
I am a little skeptical you could say because I get 20-40 gram readings on knives with 2000 grit waterstone edges, this is not even close to the level of sharpness a shaving razor needs to be. I've also had as low as 5 grams on 600 grit edges and 32 grams on machine edges (120 grit and polish).
You sure about that? Because I shave with mine. That might be a personal preference thing, because I don't grow facial hair nearly as "dense" as most and would imagine most wouldn't find it a very comfortable shave--but it works for me. I think ultimately the thickness of the edge is going to play more into shaving comfort because as it increases in thickness it will tug and pull on the hair more even if it can cleanly sever it.
Ankerson
Knife and Computer Geek
- Joined
- Nov 2, 2002
- Messages
- 21,094
I have shaved with a S30V Military more than a few times back when I was doing polished edges without much problem.
Geometry is what straight razors are all about so you are correct.
Jason B.
Knifemaker / Craftsman / Service Provider
- Joined
- Jun 13, 2007
- Messages
- 11,168
You could try shaving with one of my 2k edges but you might find it to be a poor life choice. It's a toothy/polished edge that is STRAIGHT FROM THE STONE and ideal for slicing tasks. Its like my DMT edges, they ranked with very low numbers but I can assure you that a facial shave with any of them would be painful at best regardless of hair thickness or density.
Ankerson
Knife and Computer Geek
- Joined
- Nov 2, 2002
- Messages
- 21,094
Something around 1 Micron is what I remember being recommended for straight razors, around the JIS 8K range or so.
- Joined
- Apr 3, 2011
- Messages
- 5,791
That was what was weird for me... I was getting 65 BESS score on 200 grit diamond stone but it would barely shave arm hair and definitely wasn't that comfortable lol
Jason B.
Knifemaker / Craftsman / Service Provider
- Joined
- Jun 13, 2007
- Messages
- 11,168
More like 12-15k depending on the scale.