A ''big'' question and challenge for Sal and Spyderco

[JRinFL]

I am not talking thinner stock but thinner bte. My K390 Urban is thinner bte than my Chaparrals or my Delicas...just to give an example

Yes, understood. I should have said I'd like to see more knives with thinner stock and ground thinner BTE.

[elena86]

Why are you using such a thick edge, then complaining about it to Sal?

I reprofile most my knives to 10dps or so. I think 15 dps is too thick too...........so I don't use it.

I am not talking edge angle ... I keep repeating ... whatever...

[FK]

I agree, the old time slip joint pocket knives were much thinner stock and thin BTE, liked everything about them except some had break your fingernails to open and sloppy week springs in others.
These knives were relatively soft HRc compared to Spyderco and very easy the thin out BTE, which I did quite often.

Regards,
FK

[Wartstein]

What angle do you profile them?

If all of your knives are sharpened 15 dps, the only way to change bte for a given blade height is stock thickness.

I am generally all for thin blade stocks, but don't understand your post (probably my bad! (... English... ):

Why do you think the thickness behind the edge could only be changed (reduced) if the whole bladestock thickness would change?
Regardless to what degree the knife is sharpened/reprofiled (on the actual edge), I can still reduce the thickness behind that edge, right?

[tonijedi]

Why are you using such a thick edge, then complaining about it to Sal?

I reprofile most my knives to 10dps or so. I think 15 dps is too thick too...........so I don't use it.

Because Sal only gave us the 20 and 15 degrees slots!

[FK]

Why do you think the thickness behind the edge could only be changed (reduced) if the whole bladestock thickness would change?
Regardless to what degree the knife is sharpened/reprofiled (on the actual edge), I can still reduce the thickness behind that edge, right?

If the manuf. designs the apex or primary bevel to begin at 0.028" (thickness behind the edge) it does not matter what the blade stock thickness actually is,,, if we change the angle of the blade stock to spine and thicker stock will slice less efficiently.
It also does not matter what the apex angle is (10-15-20 degrees) if the manuf. starts the apex at 0.028" BTE. We have two triangles sliding up and down in space,,,, if we fix the 0.028" BTE all the other angles and thicknesses are irrelevant. The only way to improve performance in slicing is to thin the knife blade Ref. 0.028" as shown in the reference YouTube videos.

Another point,,, if a knife is manuf with 20 degrees per side and you resharpen to 10 degrees per side,,, you have INCREASED the thickness behind the edge (where the apex meets the primary FFG). Think about it,,,,, the apex upper angle must move up the blade stock and it will now be thicker behind the edge.

Regards,
FK

[Leksy]

Here is the data of some of my knives with the most recent production dates. P4LW K390 has been reprofiled to 14 dps, the rest have a factory angle of 15 to 17 dps.

[model] (production: month.year) - [BTE near the ricasso] - [BTE at the middle] - [BTE at the tip]

Endura S30V (04.2020) - 0.018 - 0.020 - 0.024
P4LW VG10 (04.2020) - 0.020 - 0.020 - 0.026
P4LW K390 PE (04.2021) - 0.016 - 0.016 - 0.022
PM2 S30V DLC (06.2021) - 0.016 - 0.016 - 0.020
Millie S30V DLC (02.2019) - 0.016 - 0.016 - 0.024

Yes, my Civivis are 0.012 to 0.016 on average, but Spydies measures are just good too.
Also I have to mention the quality of DLC models is excellent, I can't find a single flaw to complain about.
They are much better than older variations, quite thin BTE, have great action, fit and finish.

[vivi]

Why are you using such a thick edge, then complaining about it to Sal?

I reprofile most my knives to 10dps or so. I think 15 dps is too thick too...........so I don't use it.

I am not talking edge angle ... I keep repeating ... whatever...

I know, but dropping the angle below 15 degrees would give you thinner BTE measurements....which is what you're after. Seems like a pretty obvious solution to me. I don't like how thick the factory edges are either, so I thin them out. Easy to do.

[bdblue]

Referring to this thread I think it's kind of hard to generalize that Taichung knives are all under .020" BTE and all Golden & Seki City knives are way above that. I have a lot of Taichung models and I don't think most are under .020".

This is an interesting question. I haven't noticed anything with production models but I've bought a good number of Mules and I thought I noticed that when Mule production shifted to Taichung the edges were much thinner.

[Ramonade]

Edge bevel and thickness behind the edge are not only related by a gradally bigger secondary bevel (talking on FFG). It is known that a thin stock will slice better just cause geometry. If you take a Para 3, it's not meant to cut tomatoes
IMHO, Spyderco always made knives to use in any situation, planning for the worst so you won't have to worry when it happens.

I will try the thinning method, thanks @FK ! (I won't try it on my spydercos, I like them how they are, if anyone does not, please make them visit France, I'll adopt them.

That said, I would welcome more 0.010" BTE thickness knives, with 2mm stocks. In 3" and 3.5" cutting edge s'il-vous-plaît !

[SpyderNut]

Why are Golden and Seki blades ground so thick behind the edge(most are more than 0.024'' bte) ?

Because Americans have basic tendency to taller, fatter, etc.

Hey now, I resemble that remark!

[sal]

Hi Marius,

Thanx for the challenge, and to be honest, I agree with you. But we have to consider a much larger market than knife afi's. Easier to make it thinner,than to make in thicker. Also we use more exotic steels and generally run them harder to we get complaints of nicks when too thin.

We're doing the Performance Delica to see if there is an exclusive market for high performance platforms to support making special knives for you OC, steel junkies.

sal

[Ramonade]

That will be my first Delica(s?) !

[Wartstein]

That will be my first Delica(s?) !

You are pretty new to the forum, but still I guess I know a lot already of what you like - and I am sure you WILL like the high performance Delica blade...

Here is a thread about it you might find interesting viewtopic.php?f=2&t=89435

The Delica is a great performer anyway with it's thin, 2.5 mm ffg blade.
But this version will be absolutely amazing I am sure!

[Ramonade]

That will be my first Delica(s?) !

You are pretty new to the forum, but still I guess I know a lot already of what you like - and I am sure you WILL like the high performance Delica blade...

Here is a thread about it you might find interesting viewtopic.php?f=2&t=89435

The Delica is a great performer anyway with it's thin, 2.5 mm ffg blade.
But this version will be absolutely amazing I am sure!

Soon after hearing about it I searched for it and read the whole thread But thanks for thinking about it, it did interest me a lot. You are right, I will like this Delica! (Even if I'd already like the "basic" Delica 4)

[Fireman]

Perhaps the TBE slicing performance knives have a different warranty that covers manufacturing defects but not chips and breakage? Sign an acknowledgment upon purchase? 10 thousandths BTE? Thinner than that and you are getting into Japanese kitchen knife territory and we know how those chip out (thus my love for my LC200N kitchen knives) A thicker BTE knife is better than a broken or chipped one. Will be interesting to see the edge stability and toughness of some of these knives. BBB has done some good testing in this realm. People gotta know where the rabbit hole leads to. I think a high performance steel and thin behind the edge Kapara would be a hit. I don’t think people would abuse a Kapara too much.

[elena86]

Hi Marius,

Thanx for the challenge, and to be honest, I agree with you. But we have to consider a much larger market than knife afi's. Easier to make it thinner,than to make in thicker. Also we use more exotic steels and generally run them harder to we get complaints of nicks when too thin.

We're doing the Performance Delica to see if there is an exclusive market for high performance platforms to support making special knives for you OC, steel junkies.

sal

Thank you Sal. I understand the idea behind the warranty issues and I agree with that. My idea of ''perfect'' thickness behind the edge for the ''average'' Spyderco blade would be somewhere between 0.014'' and 0.019'' depending on the blade stock thickness and the impact toughness of the used steel. I wouldn't go lower than 0.014'' just to avoid the embritllement of the apex. When I started this thread I just wanted to challenge Spyderco to ground their blades juuust a bit thinner bte for enhanced performance without compromising the edge stability. Just to give an example... the difference in performance between a PM2 blade ground at 0.018''-0.019'' (15dps) and what we usually receive from the factory(more or less 0.024'') would be notable. I wouldn't think that a PM2 blade ground at 0.018'' would be as prone to chips as some fear, regardless the steel. My Sage1 in Maxamet came ground at 0.018'' bte and sharpened at 17 dps FROM THE FACTORY. PERFECTION ! It's a joy to use that blade, never had any chips and we know that Maxamet is not a tough steel...on the contrary. Not all end users (I would say most of them) have the skills or the tools, or both, to thin out the edge as some suggested but most would enjoy using a blade as a performance oriented clean cutting(slicing) tool. God bless !

[ChrisinHove]

Have you the Watu? Thinnest bte I have .

[Wartstein]

Why do you think the thickness behind the edge could only be changed (reduced) if the whole bladestock thickness would change?
Regardless to what degree the knife is sharpened/reprofiled (on the actual edge), I can still reduce the thickness behind that edge, right?

If the manuf. designs the apex or primary bevel to begin at 0.028" (thickness behind the edge) it does not matter what the blade stock thickness actually is,,, if we change the angle of the blade stock to spine and thicker stock will slice less efficiently.
It also does not matter what the apex angle is (10-15-20 degrees) if the manuf. starts the apex at 0.028" BTE. We have two triangles sliding up and down in space,,,, if we fix the 0.028" BTE all the other angles and thicknesses are irrelevant. The only way to improve performance in slicing is to thin the knife blade Ref. 0.028" as shown in the reference YouTube videos.

Another point,,, if a knife is manuf with 20 degrees per side and you resharpen to 10 degrees per side,,, you have INCREASED the thickness behind the edge (where the apex meets the primary FFG). Think about it,,,,, the apex upper angle must move up the blade stock and it will now be thicker behind the edge.

Regards,
FK

I still disagree.. or still don´t get it (btw., no argument here who´s right or wrong! I just want to learn and understand)

- I totally agree with you as long as we are talking about a totally "true" ffg (so no convex or concave shape AT ALL starting just behind the edge and up to the spine (or where the rectangular part of a sabre grind starts)
It´s only logical and must be just by geometry as you say:
In this particular case thickness behind the edge could only be changed if the whole blade stock got thinner;
And the higher the shoulders of the grind are up (so the more acute the angle of the apex is), the thicker the knife is behind the edge.

- BUT: I think most folders are not "totally true ffgs", but slightly convex or concave starting behind the edge (and can be made MORE concave / "hollow grinded" by the end user quite easily)
IF it was the case what you say, then any Spyderco with the same blade height, blade stock thickness, tapering and grind angle would have to have the exact same thickness behind the edge. Not the case though!
AND: It was you who said in an earlier post that (quote): "Fairly easy to modify the behind the edge thickness.
Lay the knife flat on a stone,,,, raise the spine about 2-3 degrees and grind away.
The kitchen knife guys call this "thinning a knife" to make it slice better, many do this before sharpening as a routine to avoid thickening behind the edge....."
(This actually is something I do with quite some of my knives)

I am sure we must have some kind of misunderstanding here...