Page 1 of 3

Knife too thin

Posted: Thu Feb 13, 2020 9:10 pm
by Baron Mind
Unofficial pole:

Has there ever been a time when you thought to yourself, "man, that knife was too thin for that task I just did."


Follow up pole:

Have you ever experienced catastrophic blade failure on a box cutter/utility blade?

The answer for me, is no and no.

In sharpening, the rule of thumb for finding the ideal edge angle for your knife, is to consider what tasks you intend on using it for, make an educated guess for the appropriate edge angle, and put it to use. Next sharpening you lower the angle, and you repeat this process until the edge angle is too low, and the edge rolls or chips during a task it held up to before. The previous angle increment is the ideal angle for that knife, for you.

The reason we want as low of an edge angle as possible is that lowering the edge angle increases edge retention, and cutting performance in terms of force required to execute a cut.

I think this same principle can, and should be applied to knife design. Test a knife with incrementally thinner blade stock until it fails while performing routine EDC tasks.

Same thought process, thinner stock will make cuts with less resistance than thicker stock.

Spyderco makes some of thinnest knives in the industry, but I think a Delica should be in the upper or mid range of blade thickness, not the bottom.

I'd bet that kitchen knife geometry would be capable of performing 99% of common EDC use just fine. I've never broken a kitchen knife, an opinel, or a box cutter blade.

The only tasks that would concern me with that geometry is prying and batoning, and I don't advocate using a folder for either.

I am trying to keep this discussion separate from behind the edge thickness as to not muddy the waters, although they are both very important, and are related to one another.

So what do you guys think? Would you he interested in much thinner edc knife blade stock, close to kitchen knives or box cutters? I know those are extreme examples, but they illustrate the point.

Thanks

Re: Knife too thin

Posted: Thu Feb 13, 2020 9:36 pm
by fixall
Yes.

I receive dozens of pallets at work daily and sometimes the polyester and polypropylene straps are so tight, the only way to cut them loose are to angle your knife in a way that you'd prefer not to. every time I bring one of my beloved GEC slipjoints to work I'm reminded why I don't do that on a regular basis. Sometimes even the Chaparral feels a little thin at work. I've definitely fractured box cutter blades in the past.

Lately I've been bringing either my M4 or M390 Para 3, Cruwear Native 5 to work... Or if I know I have a day where I'll be opening a lot of boxes, rather than cutting straps I'll bring either my S30V or Hap40 wharncliffe Delica.

Re: Knife too thin

Posted: Thu Feb 13, 2020 9:53 pm
by sal
Baron Mind wrote:
Thu Feb 13, 2020 9:10 pm

Same thought process, thinner stock will make cuts with less resistance than thinner stock.

Hi Baron Mind.

Did you mean; "Thnner stock will make cuts with less resistance than thicker stock"?

sal

Re: Knife too thin

Posted: Thu Feb 13, 2020 9:59 pm
by rbb2
Yes to both questions. I appreciate a thin slicer, but as far as the things I use a pocket knife for I'd generally prefer medium to thick over thin for general use. Err on the side of caution, if you will.

Re: Knife too thin

Posted: Thu Feb 13, 2020 10:31 pm
by Baron Mind
sal wrote:
Thu Feb 13, 2020 9:53 pm
Baron Mind wrote:
Thu Feb 13, 2020 9:10 pm

Same thought process, thinner stock will make cuts with less resistance than thinner stock.

Hi Baron Mind.

Did you mean; "Thnner stock will make cuts with less resistance than thicker stock"?

sal
Yes I did. OP edited. Thanks!

Re: Knife too thin

Posted: Thu Feb 13, 2020 10:35 pm
by Baron Mind
fixall wrote:
Thu Feb 13, 2020 9:36 pm
Yes.

I receive dozens of pallets at work daily and sometimes the polyester and polypropylene straps are so tight, the only way to cut them lose are to angle your knife in a way that you'd prefer not to. every time I bring one of my beloved GEC slipjoints to work I'm reminded why I don't do that on a regular basis. Sometimes even the Chaparral feels a little thin at work. I've definitely fractured box cutter blades in the past.

Lately I've been bringing either my M4 or M390 Para 3, Cruwear Native 5 to work... Or if I know I have a day where I'll be opening a lot of boxes, rather than cutting straps I'll bring either my S30V or Hap40 wharncliffe Delica.
Thick plastic banding is a good point. You could argue tin snips are a better option for that task, but I won't, because you can't be lugging around a tool bag at all times, hence the point of an EDC knife.

Re: Knife too thin

Posted: Thu Feb 13, 2020 10:54 pm
by BornIn1500
I understand that office-type guys want to see dainty, thin blades, but it's not only prying and batoning that can make a blade fail. For instance, recently I was deboning a turkey with a very thin Victorinox paring knife and when I put significant downward force on the blade it started to flex. I wasn't prying anything and I sure wasn't batoning that turkey. It was just too thin for the downward force that was applied. I think a folding knife needs to be able to handle more than slicing paper. It needs some rigidty. A very thin kitchen-like folder would have to be babied. But who knows... maybe one day we'll see the Spyderco Cubicle.

Re: Knife too thin

Posted: Thu Feb 13, 2020 11:19 pm
by Pancake
BornIn1500 wrote:
Thu Feb 13, 2020 10:54 pm
and I sure wasn't batoning that turkey.
Real man would have baton that turkey with Spyderco Province and piece of log :D

Re: Knife too thin

Posted: Thu Feb 13, 2020 11:47 pm
by Wartstein
Baron Mind wrote:
Thu Feb 13, 2020 9:10 pm
Has there ever been a time when you thought to yourself, "man, that knife was too thin for that task I just did."

Follow up pole:
Have you ever experienced catastrophic blade failure on a box cutter/utility blade?

The answer for me, is no and no.
Perfectly said and you´re really speaking from my heart. I´ve been advocating for more thinner blade-stock-Spydies several times and through several polls already (for example for a Chap XL - 2mm blade stock)

In an Endura sized folder blade the 3mm this knife offers, and in an Chaparral sized folder blade the 2mm this knife offers, are more than strong enough, and I am really NOT the "office type guy" Bornin 1500 mentions in his post, but tested both knives in various "hard use" tasks (including twisting and turning the the blades in harder material and a lot of outdoor tasks)

Of course even batoning is no problem for that thinner blades (but perhaps for the lock if you don´t unlock it beforehand), it´s just not as effective as with a thicker blade.

Sure cutting performance is not only determined by blade stock thickness/thinness, but a thinner blade will always be a factor and foundation for a good slicer in a way that a thick blade just don´t offer.

Only thing a thicker blade is maybe "better": It´s more comfortable to put the finger on the spine...

The only area of a blade one has realistically to be worried about (in a folder) when it comes to breaking / snapping it is the very tip.

To be honest: This is one of the main reasons why I don´t get all the variants the Para 3 gets. Cool knife, no doubt, but for such a small folder totally overbuilt thick blade stock (more than 40 % thicker than a Delica, more than 80 % than a Chap - and WHO has ever broken a Delica blade?!), that decreases slicing performance, enhances weight, but STILL has a rather fragile tip...a bit of a "design flaw" imho for a small folder, compared to other great smaller Spyderco options (as said: Delica, Sage, Chap).
IF I´d choose to carry such a thick blade (I wouldn´t, but IF), I´d want in return for the decreased slicing performance at least a "real prybar" and not a tip that would snap rather easy.

And look at many "oldtimer folders", that people really used for any knifetask thinkable: Very often thin stock, they would not have done that for a long time if it was not strong enough..

Re: Knife too thin

Posted: Thu Feb 13, 2020 11:47 pm
by Bloke
Baron Mind wrote:
Thu Feb 13, 2020 10:35 pm
Thick plastic banding
Image

Re: Knife too thin

Posted: Thu Feb 13, 2020 11:53 pm
by Doc Dan
I’ve snapped a few box cutter blades. I think many people experience this. I’ve broken the ends, not just tips, on stout fixed blades doing nothing in particular. It was probably the heat treat on them, I think.

But, thin blades cut. I do not think of the chaparral as being too dainty after some of the workouts people on this forum have put theirs through, and it has a real thin blade.

Re: Knife too thin

Posted: Fri Feb 14, 2020 12:00 am
by zhyla
There’s kitchen blade geometry and then there’s really thin kitchen blades. The thin stock and thin behind the edge of a good kitchen knife can work well for some EDC. But, for instance, the 8 dps I sharpen my petty knives at won’t hold up for general EDC.

Anyways, Chaparral FTW.

Re: Knife too thin

Posted: Fri Feb 14, 2020 12:00 am
by Wartstein
BornIn1500 wrote:
Thu Feb 13, 2020 10:54 pm
I understand that office-type guys want to see dainty, thin blades, but it's not only prying and batoning that can make a blade fail. For instance, recently I was deboning a turkey with a very thin Victorinox paring knife and when I put significant downward force on the blade it started to flex. I wasn't prying anything and I sure wasn't batoning that turkey. It was just too thin for the downward force that was applied. I think a folding knife needs to be able to handle more than slicing paper. It needs some rigidty.

Said it in my post above: I am not at all the "office-type guy", but have tested both Endura ffg (3mm stock) and Chap (2mm stock) in outdoor, hard use, blade twisting and yes, also deboning tasks. Perfectly adequate, no problem, no irritating flexing. Sure, if you´re talking about a real thin (maybe 1mm) and long kitchen knife you´re right.
But in a folder imho (and I KNOW this from a lot of practical experience) 2mm for a smaller, and probably 2.5 mm (at least 3 mm) for a larger one are strong enough and make for superior performers.

Look at how thin "oldtimer folders", used in any knife task, often times were/are...

It may be sound provocative, and I am explicitly NOT (!) referring to you, but I think it´s sometimes exactly the "office-type guys" who want a crazy thick blade in a small folder, cause then they feel "prepared for any hard use task in this wild world", without ever really having done such tasks or harder outdoor use and not knowing what is really sufficient here (to be clear: Not trying to make fun of anyone here! Of course it´s totally fine if one enjoys to carry a tank like knife with thick blade, regardless if overbuilt or not)

Re: Knife too thin

Posted: Fri Feb 14, 2020 12:01 am
by fixall
Baron Mind wrote:
Thu Feb 13, 2020 10:35 pm

Thick plastic banding is a good point. You could argue tin snips are a better option for that task, but I won't, because you can't be lugging around a tool bag at all times, hence the point of an EDC knife.
Tin snips would definitely be a more ideal approach, as would a box knife with a hook utility blade... but like you said, I don’t have the space in my pockets to carry a niche blade for each situation. A knife with thicker stock takes care of the straps while still be able to do a solid job breaking down boxes.

That being said, outside of cutting those darn straps, I typically prefer the thinnest stock I can get. The slicier the better! That’s why the Chaparral is my favorite Spyderco of all time and is why I am so excited for the upcoming Watu. I’ve been trying to make the case for using really tough, stable steel over edge retention so we can blades can be made even thinner for awhile now. :) Geometry > everything when it comes to cutting imo.

Re: Knife too thin

Posted: Fri Feb 14, 2020 1:26 am
by VooDooChild
Im going in the opposite direction. For the record I think there is a really good middle ground between too thick and too thin.

I have definitely broken razor blades. I have had cutting task I would not subject a kitchen knife to. For me even a folding pocket knife is something that needs to be able to take a good amount of abuse.

I also dont think full flat grind is the end all be all blade geometry. I personally wouldnt mind if spyderco had a handful of thicker blade stock options as well.

I recall reading somewhere a while back that, most of us could get away with a razor blade 90% of the time. I think this is what you are sort of getting at. I dont necessarily disagree with that statement. It is just that 10% of the rest of the time that I want or need something more robust.

Where is the balance and what do you have to sacrifice on one side of the equation or the other. I would rather have something less likely to break even if it doesnt slice as well as something thinner. Then we have to ask how far do we take this idea until we end up with a sharpened prybar.

Re: Knife too thin

Posted: Fri Feb 14, 2020 2:04 am
by standy99
Being a butcher and using a knife until it’s nearly worn out, there was two reasons a knife would get shelved. To short or to thin.
A sharp knife will always cut no matter how thick.

Boning and slicing I want a knife with a bit of flex but not too much.

Pocket knife I don’t want any flex at all.

To me a pocket knife is the lump hammer of the tool world
Sledgehammer is the kitchen knife
Normal claw hammer is the butchers knife
Pin hammer is the pairing knife.

Re: Knife too thin

Posted: Fri Feb 14, 2020 2:58 am
by emanuel
I appreciate a thin knife for its specialized utility, and I find them way more pleasurable to use (I hope one day I'll get a BBB Mini Trapper :D ). But for EDC use I generally like a bit of stiffness; everyday tasks with a knife don't involve just pure slicing, but also a lot of push cutting in weird angles and light leverage. Would I be hesitant to get a thin blade for EDC? No. But that's just because I understand the limit of my knives and how to use them properly based on their design/geometry.

Re: Knife too thin

Posted: Fri Feb 14, 2020 3:18 am
by Wartstein
VooDooChild wrote:
Fri Feb 14, 2020 1:26 am
Im going in the opposite direction. For the record I think there is a really good middle ground between too thick and too thin.

........

Where is the balance and what do you have to sacrifice on one side of the equation or the other. I would rather have something less likely to break even if it doesnt slice as well as something thinner. Then we have to ask how far do we take this idea until we end up with a sharpened prybar.
emanuel wrote: I appreciate a thin knife for its specialized utility, and I find them way more pleasurable to use (I hope one day I'll get a BBB Mini Trapper :D ). But for EDC use I generally like a bit of stiffness; everyday tasks with a knife don't involve just pure slicing, but also a lot of push cutting in weird angles and light leverage. Would I be hesitant to get a thin blade for EDC? No. But that's just because I understand the limit of my knives and how to use them properly based on their design/geometry.
Totally with both of you in the matter!!

But in my personal view and experience 2mm stock for small folders and especially 3mm for large folders OFFER already the perfect "balance" and "middle ground" and are absolurely strong and stiff enough...

Again: Who has ever broken a 3mm Endura blade? Or felt that the blade itself (not the whole knife) was not stiff enough but "flexy" (honest question)

For me a "too-thin-EDC-folder" would be like a really thin (1mm and thinner), specialized, flexy kitchen knife...

So, as you rightly say: The question is rather WHAT is too thin for a certain person, and what is adequate.
My experience (and I put my knives through a lot): Endura ffg and Chap DO have thick enough blades...

Re: Knife too thin

Posted: Fri Feb 14, 2020 3:52 am
by The Deacon
Knife too thin, yes. Blade too thin on a pocket knife, never. Thin knives feel great in the pocket, but can be less comfortable in the hand for prolonged use than knives with thicker, more hand filling, handles. As for breakage, yes, I've broken box cutter and X-Acto blades, but always when doing stupid stuff. Also broke more than a few single edge razor blades cutting balsa and plastic back in my model building days. So yes, there can be such a thing as too thin for the intended purpose or the user's skill level.

Re: Knife too thin

Posted: Fri Feb 14, 2020 3:55 am
by kwakster
Maybe Spyderco could make something comparable:

https://www.bladeforums.com/threads/vin ... t-19332475