OK, it's time to get serious

[captnvegtble]

I would love to see a knife that Jazz describes (agree with no choil)... sounds like the Centofate 4?
https://www.spyderco.com/catalog/detail ... roduct=201

[Jazz]

I would love to see a knife that Jazz describes (agree with no choil)... sounds like the Centofate 4?

Perhaps a tad thin, and mine has clip sliding going on.

[Evil D]

Thanks for the discussion, Sal. First, if anyone pays attention to Mr. Janich's explanations on straight edges in slicing, they'll know about how they cut to the tip and don't slide off. Another reason I want a wharnie for work is this: when inserting the tip in tape or whatever, with the straight edge the tip is already there - with a belly, you have to lift your hand a fair amount to get the tip inserted. Here are 2 pics to show what I mean. The edge of the desk is the "box or tape, etc."...

I completely agree about the cutting power of a straight edge...that's just physics and can't really be argued with for the most part. There is however one detail that I think you're overlooking, that I'm going to talk about..not to talk you in or out of any other design, but because there was a time when I was like you and all I wanted to carry was a wharnie, mostly because of the exact thing you mentioned about getting the tip down into a box.

What I realized is that the shape of the edge/belly is not the whole issue, but rather the angle of the blade and tip in relation to the handle, or positive angle (blade sweeping upwards from the handle, like the new Spydiechef) as opposed to a negative blade angle that sweeps downward from the handle (like a Massad Ayoob).

So, lets look at two knives as an extreme comparison of this, and hopefully after this you'll see why I've chosen to EDC a Manix 2, because I believe it gives you the best of both worlds.

First, we have a wharnie. Forgive me for using a non Spyderco, but this is a great example. We have the Kershaw Needs Work:


Notice that while it is a wharnie blade like you and I both like, it has a very positive blade angle in relation to the handle. This means that you're still going to have to angle your hand up high in order to get the tip down onto a cutting surface.

Next lets look at the Massad Ayoob:


Because of the extreme negative angle on this blade, the tip is positioned way down in relation to the handle. This means that despite having quite a bit of belly, you'll be holding your hand/wrist at a very reasonable angle in order to get the tip down onto a cutting surface.


What I look at very closely in pretty much every knife I buy is the tip location in relation to the handle. On some knives like the Delica and Manix 2, the blade may have some belly but the tip is still positioned pretty low. Spyderco also seems to be pretty generous with the negative blade angles, as most of their designs are more on the negative side than positive side. This has a few benefits beyond just getting the tip lower, as it also adds power to draw cuts in a similar way that a wharnie does. As Micheal Janich has explained here, a wharnie cuts with full power all the way to the tip, BUT that's only true when the angle of the blade is even with or has a negative angle in relation to the handle. That Kershaw Needs Work is not going to cut with the same power as a Yojimbo 2 in a slashing arch because despite having a straight edge, the tip is still angled AWAY from the direction of the cut. On some knives, the angle of the blade can compensate for the straight vs. belly edge issue by lowering the tip, which means the tip will be doing as much cutting power as a straight edge would be as long as they're both positioned at the same angle in relation to the handle. On a blade that has a belly, the tip may still be cutting with less power than the rest of the belly, but that's only because the belly is cutting with even more power.

Man I hope that made sense. Anyway, the conclusion I came to was that the blade angle on a Manix 2 was actually lower than a Yojimbo 2 in relation to the handle, which means I don't have to hold my wrist any higher to get the point to penetrate into something. I also end up with just enough belly to make it more versatile than a wharnie, which does come in handy at times. My point of all this is just that the curve of an edge is only part of the story when it comes to getting the tip down into a box to cut it open.

[Jazz]

I see your points, Dave.I forgot to mention how ridiculous I think the Kershaw Needs Work's blade angle is. With that one, you have to really lift it up. I also dislike the other extreme angle too, like the Ayoob. I should mention, the wharnie also excels at opening clam packaging, which I do a lot of. Do you have a steel preference, or any thoughts to add to the specs - size, thickness, etc.?

[Ankerson]

steel? - I have no idea - I haven't tested different steels on extensive cardboard cutting, etc. - maybe Ankerson or Evil D can chime in here - anything tough, good edge holding, and not chippy

Well cardboard can be interesting as some can be very abrasive while others not so much so it's a large variable.

Contrary to popular belief, urban legends and other assorted things I have found the following to be true:

1) Corse edges work better and hold sharpness (bite) much longer.

2) You want something with a higher carbide content, think S30V and higher.

3) Use normal edge geometry around 15 to 20 degrees per side.

4) Thinner the blade the better to a point.

5) Cardboard has a lot of garbage in it and it will vary.

6) The higher carbide steels are not as chippy as some want people to think they are. (Sharpening has a lot to do with that)

7) Higher carbide steels don't lose that high sharpness level faster than the lower carbide steels.

8) Toughness is vastly over rated in the knife industry.

All of this is subjective depending on the actual knives and steels used, person using the knives and sharpening etc.

I would put CPM 10V and CPM S125V up against anything else cutting cardboard personally from what I have seen in testing. That's extreme amounts of cardboard cut..... Over a linear mile and still had a lot of bite and sharpness left.

[timlara]

P.S. Anyone else notice photobucket is NOT cooperating lately?

I usually have better luck with Imgur. They seem to either have better capacity or less traffic or something because they've been more reliable than photobucket in my experience.

http://imgur.com/

Interesting discussion...I want to keep those photos coming! :)

[anagarika]

Evil/David,

Thanks for elaborating tips vs angle, I learn something new.

No disagreement and I am only guessing here, but it seems that Jazz needs the tip to start the cut exactly where it is. If that's true, the the Ayoob might not do as the belly might touch the tape first before the tip.

[Jazz]

Jazz needs the tip to start the cut exactly where it is. If that's true, the the Ayoob might not do as the belly might touch the tape first before the tip.

Yes - well put.

Ankerson - thanks for the input. I'm thinking any steel that'll hold an edge is fine. How's. S110V on cardboard, or Cruwear?

[Ankerson]

Jazz needs the tip to start the cut exactly where it is. If that's true, the the Ayoob might not do as the belly might touch the tape first before the tip.

Yes - well put.

Ankerson - thanks for the input. I'm thinking any steel that'll hold an edge is fine. How's. S110V on cardboard, or Cruwear?

S110V is excellent.

Like I said from the S30V/S35VN range and up ideally.

[Jazz]

Wow. If it was S110V and blue FRN, I'd love it even more.

[Ankerson]

Wow. If it was S110V and blue FRN, I'd love it even more.

S110V is very nice and it's good that Spyderco is using it.

Sharpening is very important, getting a clean apex is vastly important.

If they make it thin behind the edge as in .015" or thinner it will really be something. Thin just glides through cardboard like nothing else. :)

Almost like one isn't even cutting anything.

[Jazz]

I forgot to mention something some will think odd - it should be easy to open two-handed as well as a nice, large thumb hole. I took a Stretch to work to try out, and as I do a lot, went to open it two-handed. Try that with a Stretch. Not much to grab onto. Of course, wharnies usually stick out a fair bit, so it shouldn't be an issue.

[Ankerson]

I forgot to mention something some will think odd - it should be easy to open two-handed as well as a nice, large thumb hole. I took a Stretch to work to try out, and as I do a lot, went to open it two-handed. Try that with a Stretch. Not much to grab onto. Of course, wharnies usually stick out a fair bit, so it shouldn't be an issue.

I think what is missing here is that Spyderco has to think about the masses and who might be buying this knife, that's looking outside of the Forums.

So I think things need to be kept reasonable, that's my opinion, and why I said S35VN is fine and should be reasonable to sharpen while still having good edge retention for the masses.

That's taking into count the masses.

[Waco]

Does the Manix 2 really have too much belly for these tasks? it may not be a back lock, but it fits all the other criteria perfectly.

Of the Spydercos I've owned, the Manix 2 feels the most like a utility knife.

[Evil D]

I see your points, Dave.I forgot to mention how ridiculous I think the Kershaw Needs Work's blade angle is. With that one, you have to really lift it up. I also dislike the other extreme angle too, like the Ayoob. I should mention, the wharnie also excels at opening clam packaging, which I do a lot of. Do you have a steel preference, or any thoughts to add to the specs - size, thickness, etc.?

I'm with Jim on liking the S30V and up steels especially for things like cardboard. I do also like simple high carbon steels like 1095 etc, VG10 is a great all purpose steel. If you're good at sharpening them S110V will serve you well.

[Jazz]

I can sharpen anything I've encounterd just fine, but like y'all said, it wouldn't just be for us afis. Then again, it's for serious cutting - should be a good steel.

[Evil D]

I can sharpen anything I've encounterd just fine, but like y'all said, it wouldn't just be for us afis. Then again, it's for serious cutting - should be a good steel.

I think the best thing to do is really think about how your edges have been in the past...have they chipped a lot, do you bang them on staples and stuff like that? There's a good argument about ease of sharpening vs. edge retention when it comes to having to fix damaged edges after every time you use a knife. My last job I had to cut plastic bags off a steel grate everyday and it was impossible to not mess the edge up on that grate, so I stopped using steels like S110V because it just wasn't worth fixing the chips and flat spots in the edge. For that I used SE H1 and it really did a great job protecting the edge and the steel was tough enough that none of the teeth chipped. I don't think I'd have been happy with PE H1 in that situation but another steel like VG10 or Cruwear or 3V would have held an edge well enough and been plenty tough to survive being dinged on the steel grate all day.

[Jazz]

I'm my job, I've only hit a staple once, and it upset me enought to be wary. For me, I'd go with edge holding and tough enough to survive a drop on concrete. Obviously, any knife'll chip on the tip if hitting concrete, but it should be somewhat tough. Wharnies are easy to fix if the point is damaged, too.

[sal]

Hi Jazz,

While there is still much to discuss, my next question is; if we make a proto using a Delica 4 handle with a full flat warnie blade, will you test it at wrk and report in detail?

BTW, a warnie blade isn't going to stick out much more than a Stretch when closed. We could design two hand opening into the blade, eg: a double dent near the tip of a wider blade?

sal

[captnvegtble]

Hi Jazz,

While there is still much to discuss, my next question is; if we make a proto using a Delica 4 handle with a full flat warnie blade, will you test it at wrk and report in detail?

sal

That sounds pretty sweet!