Uneven Bevel On My Paramilitary 2

My native has a similar bevel issue. I have no real problems sharpening it. It sharpens up really nice and cuts well, just looks a little funny. Honestly, not worth sending in unless you find yourself unable to get it sharp
 
I received a Benchamde 520 that had some funky bevel geometry. I walked it in their door and they handed me a new knife without me asking for one.

I'd rather have a scratch on the knife than a munged up bevel. If your knife is anything as bad as this guy's
chambelona59 said:
My post from a year ago with pictures of the two bevels:
http://www.bladeforums.com/forums/showthread.php/1028648-On-a-new-Para-Military-2-should-the-bevel-edges-look-the-same-on-both-sides?p=11729184#post11729184
Click to expand...
I would send it back and have them deal with it.

BUT, I am VERY particular about my edges. A bevel ground as shallow as chambelona's can produce a weak, albeit very sharp, edge, and will require a LOT of reprofiling to be rid of. This shortens the "life" of the blade. I'd be livid if I had to take >1mm of expensive steel off of a NEW knife.
 
I reprofile EVERYTHING at this price point. And since all I buy is stuff at this pricepoint and below...that's EVERYTHING. So if it's sharp, use it until it's dull and then reprofile it.
 
Cypress said:
I received a Benchamde 520 that had some funky bevel geometry. I walked it in their door and they handed me a new knife without me asking for one.

I'd rather have a scratch on the knife than a munged up bevel. If your knife is anything as bad as this guy's

I would send it back and have them deal with it.

BUT, I am VERY particular about my edges. A bevel ground as shallow as chambelona's can produce a weak, albeit very sharp, edge, and will require a LOT of reprofiling to be rid of. This shortens the "life" of the blade. I'd be livid if I had to take >1mm of expensive steel off of a NEW knife.
Click to expand...

And not all of us are skilled/great at 're-profiling' I'm not embarrassed to admit.
I'm great at sharpening, but actually re-profiling the blade I'd rather send it back, most likely they'll send me a new knife which is fine by me.
Interesting point you made re:
"can produce a weak, albeit very sharp, edge, and will require a LOT of re-profiling to be rid of."
Click to expand...
 
On a $50.00 knife, I wouldn't worry much about sloppy grinding and poor quality control. On a knife who's street price is well over $100.00, I'd either send it back to the retailer and get a refund, or send it to Spyderco for replacement...not repair, but replacement.
 
Luis G. said:
If one side is ground far more than another at a different angle, do you think the edge is aligned properly with the spine? It's not.
This can introduce a good chunk of lateral pressure on the edge when pressing straight down. Remember pressure is dependent on surface area, so the edge can easily be put to hundreds of pounds per square inch. It is important to have the edge centered and straight to help keep the edge long lasting.
Click to expand...

This sounds incorrect to me. How do you explain the lack of failures with chisel-ground edges?
The Emerson forum has no complaints of premature dulling and neither do my actual chisels.

I'm sure, in a perfect world, that absolutely centered edged could potentially last longer. Since we are imperfect humans and not a single one of us can use a knife without laterally stressing the edge, perfectly centered edges don't affect edge longevity one bit.
Centered or not, lateral loading will happen anyway.
 
If you think it's off enough and don't have faith to fix it yourself then seek the warranty department. As somebody posted, fixing an expensive s30v edge out of box is unacceptable to some people.
 
Nullity said:
This sounds incorrect to me. How do you explain the lack of failures with chisel-ground edges?
The Emerson forum has no complaints of premature dulling and neither do my actual chisels.

I'm sure, in a perfect world, that absolutely centered edged could potentially last longer. Since we are imperfect humans and not a single one of us can use a knife without laterally stressing the edge, perfectly centered edges don't affect edge longevity one bit.
Centered or not, lateral loading will happen anyway.
Click to expand...

What does a chisel grind have to do with a v grind?
 
Luis G. said:
What does a chisel grind have to do with a v grind?
Click to expand...

It was in reference to your comment about an off center edge being more prone to wear due to uneven forces on the edge. A chisel grind, by nature is an off center edge, and since many knives, including most Japanese kitchen knives as well as emersons (which are generally thought of as hard use knives...not exactly weak) use a chisel edge, saying that a chisel edge is fundamentally worse is not exactly true.

But this conversation isn't about physics and the benefits of different grind styles, it's about a para2 with a slight quality control issue. What it all boils down to is if you can fix it yourself, there's no need to send it in to spyderco. If you can't fix it yourself and you know it will bother you, then send it in to get fixed. Simple as that.
 
Luis G. said:
What does a chisel grind have to do with a v grind?
Click to expand...

A chisel grind is simply a v-grind at a slight angle. This, according to what you said, should significantly affect edge retention because of the significant lateral stresses compared to a v-edge.

My point was that real world variables (dominant hand, steel type, hand strength, proper technique, etc) are much more important than slight asymmetry at the edge bevel. I disagree that "It is important to have the edge centered and straight to help keep the edge long lasting." Lateral loading will always be a factor, with a slightly (a few thousandths of an inch) off-center edge apex having very little real-world impact.
 
Nullity said:
A chisel grind is simply a v-grind at a slight angle. This, according to what you said, should significantly affect edge retention because of the significant lateral stresses compared to a v-edge.

My point was that real world variables (dominant hand, steel type, hand strength, proper technique, etc) are much more important than slight asymmetry at the edge bevel. I disagree that "It is important to have the edge centered and straight to help keep the edge long lasting." Lateral loading will always be a factor, with a slightly (a few thousandths of an inch) off-center edge apex having very little real-world impact.
Click to expand...

It is not just a V grind at an angle. That is completely incorrect. A chisel grind is a completely different geometry and cutting function compared to a V grind. A chisel grind only pushes one side of the material being cut while the other side remains unaffected. On a V grind BOTH sides are pushed away thus BOTH sides of the blade are affected by friction and pressure.
The reason they are different is because on a V grind you require BOTH sides to be even if they are not even, they offset the edge. Compare that to a chisel ground which does not matter because one side is flat.

What I am saying is if you take the paramilitary 2 it is flat ground on both sides. If you split the blade in half on the length of the spine you will theoretically end up with two equal parts with equal tapers and thickness.
If one side is ground to 20 degrees, and another side is ground to 20 degrees and you take care to set the bevel to the same width. the edge will be dead smack in the middle and be centered. Lateral stresses will not be a major issue.

If you grind on side to a different angle it requires more or less material to be removed to reach the edge and you will end up with a crooked edge. even if you take care not to end up with a crooked edge, it will be off set and will be prone to lateral stresses due to the differences in bevels (will be very very dramatic to get an even edge when the angles don't match).

This makes the edge crooked not centered nor straight. This is what I meant by increasing lateral stress.
Both edges will last the same, just in heavier use, the one that is crooked will be far more prone to nicks and rolls because of that added lateral stress.

It will also cause issue when sharpening using a microbevel. (more prone to stubborn wire edges, far more prone).

Lastly forgot to mention:
A few degrees (thousandths of an inch of the edge) can mean the difference between double digit percentages in edge retention. (16~ vs 20 degrees on a .010 behind the edge, you are talking about .01-.02") difference barely to the thickness of the bevels.
 
Last edited:
Luis G. said:
It is not just a V grind at an angle. That is completely incorrect. A chisel grind is a completely different geometry and cutting function compared to a V grind. A chisel grind only pushes one side of the material being cut while the other side remains unaffected. On a V grind BOTH sides are pushed away thus BOTH sides of the blade are affected by friction and pressure.
The reason they are different is because on a V grind you require BOTH sides to be even if they are not even, they offset the edge. Compare that to a chisel ground which does not matter because one side is flat.

What I am saying is if you take the paramilitary 2 it is flat ground on both sides. If you split the blade in half on the length of the spine you will theoretically end up with two equal parts with equal tapers and thickness.
If one side is ground to 20 degrees, and another side is ground to 20 degrees and you take care to set the bevel to the same width. the edge will be dead smack in the middle and be centered. Lateral stresses will not be a major issue.

If you grind on side to a different angle it requires more or less material to be removed to reach the edge and you will end up with a crooked edge. even if you take care not to end up with a crooked edge, it will be off set and will be prone to lateral stresses due to the differences in bevels (will be very very dramatic to get an even edge when the angles don't match).

This makes the edge crooked not centered nor straight. This is what I meant by increasing lateral stress.
Both edges will last the same, just in heavier use, the one that is crooked will be far more prone to nicks and rolls because of that added lateral stress.

It will also cause issue when sharpening using a microbevel. (more prone to stubborn wire edges, far more prone).
Click to expand...
"A chisel grind only pushes one side of the material being cut while the other side remains unaffected. On a V grind BOTH sides are pushed away thus BOTH sides of the blade are affected by friction and pressure."
Click to expand...
 :thumbup:
 
I think we've both said our part. I'm done. :)

@It'sPete,
I would choose #3. If you want perfection from the factory you either need to get lucky or spend more money, sadly. I don't like it but I assume all knives will have an uneven edge bevel. It doesn't effect function and it is easily remedied if it really bothers you. If you're obsessive it's hard to beat the calming effect of a perfectly symmetrical, mirrored edge bevel. :D

(Image stolen from knifenut1013)
Picture1283.jpg
 
Good Gowd, Man! Hurry, attain the help of a lawyer, and SUE SPYDERCO!!! Darn company sends you a pocket knife that is shaving sharp, but is IMPERFECT!!!! A mob formed in my city just reading thing, and they're leaving a swath of destruction all the way to Golden, CO! Call the President! Hurry! Time is running out! Your life depends on this choice, and you can't wait for suggestions here! Not enough time! RUN! Rent a plane and go to CO, man! Pound down the CEO's door NOW! This is no joke! I here the simple fact that you have an imperfect bevel is causing us to support rebels in Syria!! I've got to dig my bunker!!!!


The knife works. Use the friggin thing and live with it. Put down the Micrometer and microscope, Poindexter. Holy Carp, I am so tired of this kind of whining. I am glad I just get a knife and ignorantly use it without sending it out for an in depth perfection inspection before enjoying it. Life is easier that way.
 
Nullity said:
This sounds incorrect to me. How do you explain the lack of failures with chisel-ground edges?
The Emerson forum has no complaints of premature dulling and neither do my actual chisels.

I'm sure, in a perfect world, that absolutely centered edged could potentially last longer. Since we are imperfect humans and not a single one of us can use a knife without laterally stressing the edge, perfectly centered edges don't affect edge longevity one bit.
Centered or not, lateral loading will happen anyway.
Click to expand...

Luis G. said:
What does a chisel grind have to do with a v grind?
Click to expand...

Nullity said:
A chisel grind is simply a v-grind at a slight angle. This, according to what you said, should significantly affect edge retention because of the significant lateral stresses compared to a v-edge.

My point was that real world variables (dominant hand, steel type, hand strength, proper technique, etc) are much more important than slight asymmetry at the edge bevel. I disagree that "It is important to have the edge centered and straight to help keep the edge long lasting." Lateral loading will always be a factor, with a slightly (a few thousandths of an inch) off-center edge apex having very little real-world impact.
Click to expand...

Luis G. said:
It is not just a V grind at an angle. That is completely incorrect. A chisel grind is a completely different geometry and cutting function compared to a V grind. A chisel grind only pushes one side of the material being cut while the other side remains unaffected. On a V grind BOTH sides are pushed away thus BOTH sides of the blade are affected by friction and pressure.
The reason they are different is because on a V grind you require BOTH sides to be even if they are not even, they offset the edge. Compare that to a chisel ground which does not matter because one side is flat.

What I am saying is if you take the paramilitary 2 it is flat ground on both sides. If you split the blade in half on the length of the spine you will theoretically end up with two equal parts with equal tapers and thickness.
If one side is ground to 20 degrees, and another side is ground to 20 degrees and you take care to set the bevel to the same width. the edge will be dead smack in the middle and be centered. Lateral stresses will not be a major issue.

If you grind on side to a different angle it requires more or less material to be removed to reach the edge and you will end up with a crooked edge. even if you take care not to end up with a crooked edge, it will be off set and will be prone to lateral stresses due to the differences in bevels (will be very very dramatic to get an even edge when the angles don't match).

This makes the edge crooked not centered nor straight. This is what I meant by increasing lateral stress.
Both edges will last the same, just in heavier use, the one that is crooked will be far more prone to nicks and rolls because of that added lateral stress.

It will also cause issue when sharpening using a microbevel. (more prone to stubborn wire edges, far more prone).

Lastly forgot to mention:
A few degrees (thousandths of an inch of the edge) can mean the difference between double digit percentages in edge retention. (16~ vs 20 degrees on a .010 behind the edge, you are talking about .01-.02") difference barely to the thickness of the bevels.
Click to expand...

Nullity said:
I think we've both said our part. I'm done. :)

@It'sPete,
I would choose #3. If you want perfection from the factory you either need to get lucky or spend more money, sadly. I don't like it but I assume all knives will have an uneven edge bevel. It doesn't effect function and it is easily remedied if it really bothers you. If you're obsessive it's hard to beat the calming effect of a perfectly symmetrical, mirrored edge bevel. :D

(Image stolen from knifenut1013)
Picture1283.jpg
Click to expand...

Would you two just go outside and whittle a twig or something?
 
This discussion really needs pictures (good ones) if it's going to get back on the tracks.

If in doubt, send it in.

It'sPete said:
Hi guys,

I'm a long time reader, first time poster. I recently got into knives, and bought a Delica 4 a few months ago. It's been a GREAT EDC! However, I found myself looking for a big larger blade with a different lock. I found the blade shape perfect, I just wished that there was a bit more of it and I found myself wanting a finger choil.

As you can tell (from the title of this thread) this led me to a PM2. I was able to get one online and it came in a few days ago. The lockup is SOLID. I do have an issue with the knife though.

I bevel on the knife is very irregular. The knife still came shaving sharp, but the bevel on one side goes up the blade about 2-3mm more than the other side. This is occurring right by the tip. Overall, between this and the fact that the knife appears less smooth than what I've seen in some videos, I'm debating parting ways with it. Also, I have a love/hate relationship with the handle. When it's not in my hand, I think that there is too much of it, but when holding the knife I find the ergonomics perfect.

I'm wondering what I should do. Here are the options I'm considering and I'd love your opinions to sway me one way or the other.

1. Send the knife back, get a refund. Pick up a different model knife, maybe a BM 940?

2. Send the knife to Spyderco and hope they fix it. Honestly, I think the bevel irregularity might just be a function of buying a production knife and I should probably just accept it as is. I don't have high confidence that Spyderco would be able to fix the issue, as I'm fairly certain that this is well within tolerances.

3. Use it and enjoy it. When the blade gets dull, just have it re-profiled to ensure that the bevel is good to go.

Thanks for your input and helping me figure out what to do. I'm strongly leaning towards option 3 since the more I fondle it, the more I love it.
Click to expand...
 
Luis G. said:
Dont talk about wood man. I still got a .5" hot spot from cutting up some wood 2 days ago for a good while.
Click to expand...

Well then, I stand humbly corrected. Continue your, ahem, tinkling (see, Mods, censored myself) match. It's so on topic and exciting.
 
Where is the knife made? If it was made in Japan that's how they do it. Their blades are not 50/50, more like 70/30, and a lot sharper because of that.
 
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