Spyderco Forums

bearfacedkiller wrote:What about the fact that most of my Golden knives come at around 30 degrees and my Taichung knives come at 40 degrees (or sometimes more). I have had Japanese knives come in at well below 30 and above 40. I absolutely love the idea of this thread though. I am not trying to shoot the idea down but it would also be amazing if the edge angle was included too. I realize though that that is asking for a lot.

It shouldn't matter if we're comparing models directly with each other. I don't think the goal here is to find the best slicer or thinnest, it's just to have an idea what each model comes in at. Unless they start making Taichung models in Japan then the angle of the bevel won't change for a given model, and by averaging numbers we can account for human error and manufacturing tolerances.

It just seems like comparing a Mantra at 40 degrees to a Delica at 30 degrees isn't telling me as much as if all the knives in the test were at the same angle. While it isn't a huge difference the Mantra will measure out thicker with steeper angle. I have long been frustrated by the obtuse bevels on Taichung folders for this reason. They look like they are ground crazy thin and then you find out it was over 40 degrees and then when you put a 30 on it it looks more like a standard bevel. This is just the nature of flat grinds. When I first saw my S110V mule I thought it was super thin but it was just a (I'm guessing) 45 degree bevel. I put a 30 on it and it looked like all the rest. While it is a subtle change, changing the bevel angle does widen the bevel. This is more of an issue with flat grinds than hollow grinds and is a non issue with true scandi grinds. It is just geometry. Maybe I am just overthinking how much effect it actually has on the measurement?

Again, I really love this idea but I just want the data to make as much sense as possible and be as useful as possible.

Darby you're on point with that, it would be great if that were possible but then you introduce each person's sharpening techniques and the fact that reprofiling at all is going to bring you higher up into the blade so even if you did lower the bevel angle you may end up thicker behind the edge because of it. I think it may be helpful to note the angle of the bevel of each model, as you mentioned before, especially since in the past that has fluctuated a bit, but then we also need a reliable way of measuring bevels and that's a whole other topic. These numbers will be less useful comparing one model to the next and more useful just as a reference for each individual model, and then you take into account where it's made and how the bevel angle is.

I thought about adding the approximate bevel angle but I would just be eyeballing it. I've looked at and enough edges and sharpened enough at 20° that I could probably call it an educated guess but it would still be a guess.

Here are some observations....

The Taichung knives all appear to be near 20 dps. Some might be a little more as the bevel appears to be very short. Some I know are a little less. I've sharpened my Sage 1 & 2 on my old Sharpmaker 203MF which only has the 20° slots for the rods. When I sharpened them I used a Sharpie on the bevels and only 2/3 of the ink was removed. I just looked at them with a 10X loupe and confirmed. My Sage 3 & 5 appear to be about the same as the 1 & 2. The bevel on my Mantra appears to be more obtuse than the Sages as the bevel is tiny. I've touched up the Mantra on the SM and, looking at it with the loupe, the new scratch pattern only goes 1/2 way up the bevel. Go figure.

The Golden models all appear to be closer to 15 dps. In some cases maybe even less. All my Golden mfg knives have thicker blade stock than the others so I thought maybe that was the difference I was seeing. However, I've added a 20 dps micro-bevel to some (PM2 DLC, N5 G10, & both M2 BD1 LW's) and the new scratch pattern is very short compared to the rest of the bevel. So the factory bevel on those were considerably less than 20 dps.

The bevels on the Japanese knives also appear to be closer to 15 dps and, again, in some cases maybe even less. Judging by the 20° micro-bevels I've added I know the Delicas, Dragonflies, Manbugs, and Stretches are considerably less than 20 dps.

If we ignore the curvature of the bevel (if any induced by free hand), measuring the bevel length (from shoulder to apex) and BET will help determining sharpening angle (assuming quite symmetrical sharpening, not like recent Cru-Wear that David did).
BET/2 divided by bevel length is sine of the dps.

@Sharp Guy: Can you post a shot of where you are measuring spine and blade stock thickness? I'll add some digical measurements to the database accordingly.

adamlau wrote:@Sharp Guy: Can you post a shot of where you are measuring spine and blade stock thickness? I'll add some digical measurements to the database accordingly.

Hi adamlau,

Please see the description in my post on the previous page. Let me know if it's not clear.

viewtopic.php?p=1130365#p1130365

SG

PM2 M4/CF - .025 / .1435 / .1435
PM2 CRUWEAR - .025 / .1455 / .1455

Mitutoyo 500-752-10. Blade secured in a Yost table vice under 4x spot magnification from a Magniflex Pro:

PM2 M4/CF - .025 / .1435 / .1435
PM2 CRUWEAR - .025 / .1455 / .1455

[Accidental Post]

Mantra aside, my blue G10 BBS Domino seems thinner than other models.Did anyone measure a Domino ?

I almost bought a caliper for this thread but then I realized all my knives except for 2 backups are reprofiled so my numbers would be wider than most.

Great idea.

It is easy to see why I like regrinds so much after seeing the factory thickness behind the edge. I have had a few ZDP folders reground to .010" and .015" behind the edge. Those things would cut even when the edge wasn't sharp anymore. I love a good regrind. :)

Lowering the angle of the sharpening bevel will increase thickness at the shoulders of a FFG blade, because it pushes them up the primary grind. This is least true on a hollow grind, where TBE could even go down a little as you move up the grind.

Bill1170 wrote:Lowering the angle of the sharpening bevel will increase thickness at the shoulders of a FFG blade, because it pushes them up the primary grind. This is least true on a hollow grind, where TBE could even go down a little as you move up the grind.

I don't see how this would matter. It is still thinner than it was before.

You make the edge thinner in the spot that the factory bevel shoulder used to be but the new shoulder ends up higher in the blade and so it's thicker. This is why the idea of this thread really only makes sense to measure factory bevels and then then I'm sure there's a good amount of variables especially back when bevels were ground by hand. Adding the measurements of a reprofiled knife doesn't make any more sense than doing the same with a reground knife.

Sharp Guy wrote:I have a micrometer and a dial caliper along with a bunch of knives that still have factory bevel (many with a microbevel added). Where would you like me to measure? With my Mantra, when I measure down near the ricasso I get .0175-.018. When I measure out closer to the tip I'm getting .021 .020. I'm thinking that, due to blade shape, closer to the ricasso would be better. Regardless of where you'd like me to measure I think it would be best to be consistent.

Mantra: .0175-.0180. Spine at ricasso: .118

Hey SG did you measure the Domino ? It seems to be quite thin behind the edge ...

elena86 wrote:Hey SG did you measure the Domino ? It seems to be quite thin behind the edge ...

Sorry elena86, I don't have a Domino to measure. Maybe somebody else can measure that one?

Time to add a few...

As previous, the format is as follows:

Behind Edge / Spine / Blade Stock

Units are in decimal inches.

Note: The edge on most of these have all been touched up on the SM at 40° but the factory bevel remains on all unless otherwise noted.

Chaparral LW - .0175 / .073 / .0775

Caly 3 HAP40 Sprint - .022 / .111 / .116

Caly 3.5 ZDP189 CF - .0225 / .107 / .116

Positron KC Exclusive - .016 / .117 / .117

UKPK LW S110V * - .025 / .084 / .098

Advocate - .023 / .116 / .117

Sliverax * - .023 / .134 / .136

Manix 2 52100 KW Exclusive - .024 / .120 / .125

Delica Pakkawood-HAP40 KC Exc. - .017 / .086 / .096

Dragonfly Pakkawood-HAP40 KC Exc. - .020 / .0965 / .0965

Dragonfly Salt HB SE - .031 / .0965 / .0965

Urban K390 Sprint - .015 / .106 / .112

Lil Matriarch BBS Exc. - .023 / .0985 / .0985

Para 3 Cruwear Sprint - .0225 / .140 / .144

Para 3 M390 BBS Exc. - .0235 / .143 / .145

Paramilitary 2 M390 DLT Exc. - .023 / .1405 / .145

Baby Horn Sprint - .014 / .080 / .090

Manix 2 LW S110V * - .0255 / .118 / .125

* Reprofiled at approx. 13° per side. Sliverax has been reprofiled once. UKPK S110V has been reprofiled 2 times. Manix 2 LW has been reprofiled at least 3 times.

A couple notes: I was surprised at the BTE measurement for the Positron. Edge bevel appears to be approx. 15° per side. I was also surprised by the BTE measurement of the Delica Pakkawood compared to my FRN Delicas. But after comparing them the FRN knives have a much higher edge bevel. So it appears the edge on the Delica Pakkawood is much more obtuse than the FRN knives. I know it's less than 20° p.s. based on the micro-bevel it had after touching it up on the Sharpmaker. The edge bevel on the FRN Delicas are pretty close to 30° p.s. based on how they compare (visually) to another Delica I have that I've reprofiled at 15°.

Hey SG you are doing a great job. I am glad you confirmed the fact that my beloved K390 Urban is very thin bte. Now I’m considering a baby Horn sprint. I love very thin bte blades. Keep up the great job. I am very curious about the Domino.