Blade Grind: Avantages? Disadvantages? PE & SE

[JD Spydo]

About 4 years ago my good pal EVIL D made the observation that a "full flat grind" in Spyderedge worked better than any other blade grind that they put a Spyderedge on>> and after testing an FFG with a Spyderedge I tend to agree with him. There has been a lot of talk over the years with Spyderco knives and the wide selection of many different blade grinds. I've also found the "full flat grind" on a plain edged blade provides some advantages.

Now I've also had great luck with hollow grind blades in Spyderedge. But as to why the "Full Flat Grind" provides a better performance in Spyderedge is very curious to say the least. OK let's talk about the different blade grinds and how they perform in Spyderedge and Plain edge. Also list the advantages or disadvantages of each blade grind.

I find it very strange that over the years I've heard a lot of negative stuff about hollow grind blades but the ones I own in Spyderedge and plain edge both have served me very well. Also you don't hear much anymore about sabre grinds or chisel grinds>> at least not like you used to a few years back. Also which blade grinds do you all like best and list the edge type too ( Spyderedge & Plain Edge).

[Evil D]

It depends on what's being cut and how both blades are ground. Example, I wouldn't say a TUFF (if it came in SE) would slice any better than a Catcherman just because of grind difference, because overall the Catcherman is much thinner. If you're cutting something really rigid that the entire blade has to pass through, like very thick cardboard or anything that won't separate as it's being cut, then a thinner blade/grind wins regardless of edge type.

Another good example, if a Yojimbo 2 were offered in SE, and you compared it to a Para 2 in SE, both have the same blade stock thickness but my money is on the Para 2 for slicing better unless you're cutting something that easily separates or is shorter than the hollow grind is on the Yojimbo.

[Jazz]

I like FFG and other grinds if they’re high enough. I wish the Delica saber and Salt 2’s were ground higher. They’d still be tough, but get through cuts way better. I’m talking SE and PE.

Seems to me the grind is as important for slicing on one as is the other, except the thick Rescues. They’ll still cut a seatbelt great, and be tougher for prying. I really wish I had a higher ground Rescue 79mm, though.

[Evil D]

I find it very strange that over the years I've heard a lot of negative stuff about hollow grind blades but the ones I own in Spyderedge and plain edge both have served me very well.

It just depends on what you're cutting. Even then it's not like the hollow grind is completely garbage. Compare an old Calypso Jr to a hollow grind Native and see which slices double wall corrugated better.

SE vs PE really only matters at and behind the edge. After that the thinner blade will perform better and the thinner the blade is all the way up to the spine the better.

What would really be fun is a full hollow grind all the way up to the spine on 3mm stock on a tall blade like the Caribbean, ground nice and thin at the edge and then put SE on that.

[Sumdumguy]

I find it very strange that over the years I've heard a lot of negative stuff about hollow grind blades but the ones I own in Spyderedge and plain edge both have served me very well.

It just depends on what you're cutting. Even then it's not like the hollow grind is completely garbage. Compare an old Calypso Jr to a hollow grind Native and see which slices double wall corrugated better.

SE vs PE really only matters at and behind the edge. After that the thinner blade will perform better and the thinner the blade is all the way up to the spine the better.

What would really be fun is a full hollow grind all the way up to the spine on 3mm stock on a tall blade like the Caribbean, ground nice and thin at the edge and then put SE on that.

I prefer a FFG, but that does sound interesting.
I would try one out.

[vivi]

I'll take a FFG for every knife if given the option. I've avoided buying certain models from various companies because of a 1/2 height saber grind. Every knife I carry and use is FFG aside from my salts, which I find worth the trade off since they're rust proof magic.

[embry386]

I'll take a FFG for every knife if given the option. I've avoided buying certain models from various companies because of a 1/2 height saber grind. Every knife I carry and use is FFG aside from my salts, which I find worth the trade off since they're rust proof magic.

+1 to what Vivi said :spyder: I have a few hollow-ground knives which I like a lot and use as my EDC ones, but the hollow grind is not on the list of things I like about them. If they were flat-ground they'd be far more perfect and way better at everything.

[knivesandbooks]

For me, lot of it is how aggressively they're ground. I've owned and handled some saber grinds and regrinds that were ground quite aggressively, leading to a super thin edge. This compensates for a thucker stock or lower grind. However you do still have a wedge effect even if it is fifteen thousandths behind the edge. So perfection is super aggressively ground ffg in my opinion. For standard production knives and Spyderco, I prefer ffg

[JD Spydo]

I find it very strange that over the years I've heard a lot of negative stuff about hollow grind blades but the ones I own in Spyderedge and plain edge both have served me very well.

It just depends on what you're cutting. Even then it's not like the hollow grind is completely garbage. Compare an old Calypso Jr to a hollow grind Native and see which slices double wall corrugated better.

SE vs PE really only matters at and behind the edge.

Don't forget that the stainless handled version of the Caly Jr. had a hollow grind :confused: and don't ask my why out of all the Caly Jr. models that just one had it because I've been baffled by that myself. But I had that model in SE & PE both and I couldn't tell any performance difference between that one or any of the other Caly Jr. models that I had owned over the years.

But to see the profound difference that you once cited from "Full Flat Grind" blades in Spyderedge you have to go all the way back to the original C-54 big Calypso model. Because in the first runs of that model it was offered in SE and I'm here to tell you that it was a chain saw of a folder. Yeah I wish I had it back again and I'm going to make it a point to find an old one.

But talking about hollow grinds again>> don't forget that most Straight Razors have a hollow grind and look at how efficiently they work. You are correct in pointing out that whatever material you are cutting does seem to make a difference as well. But since I've been carrying and using my Stainless RESCUE model from the old ATS-55 era I've yet to confront any material I could not shred with that bad boy. Oh and by the way the Stainless RESCUE model is a "Hollow Grind" too for whatever that is worth.

[Evil D]

But talking about hollow grinds again>> don't forget that most Straight Razors have a hollow grind and look at how efficiently they work. You are correct in pointing out that whatever material you are cutting does seem to make a difference as well. But since I've been carrying and using my Stainless RESCUE model from the old ATS-55 era I've yet to confront any material I could not shred with that bad boy. Oh and by the way the Stainless RESCUE model is a "Hollow Grind" too for whatever that is worth.

Straight razors are a specialized tool designed to cut only one material, they're possibly the worst blade to compare pocket knives to.

I used to cut up a lot of boxes, and that's an area that blade grind can make a big difference. Like I said, it depends on what you cut. You'll never see any impact from blade grind if an edge never cuts anything larger than beard stubble. You won't see a difference if you're cutting rope or seat belts or anything that separates easily. Go out and find a double wall box and see which grind wedges the most. Geometry is inescapable, thinner will always bind less.

The only way it doesn't matter is if the two blades differ so much that they make poor comparisons to each other. For example if you have an FFG blade that is 4mm thick at the spine and 2 inches tall, and you compare it to a hollow grind that is also 4mm thick at the spine but the blade is 3 inches tall and the hollow grind extends all the way up to 1/4 inch from the top of the spine, then the hollow grind is likely to perform better. Even still there's the question of how thin are each grind behind the edge, since being FFG doesn't guarantee it'll be a slicing machine if it's ground thick, those 4mm blades won't slice very well if they're 2mm thick behind the edge.

[Jazz]

Well put, Dave. I cut tons of cardboard of varying thicknesses, double walled, etc., and that’s where thinner shines. No need for a big ol’ Wedge there. Seat belt, different story.

[JD Spydo]

I beg to respectfully differ with your take on straight razors. Many of the gangsters and thugs in the day preferred straight razors as offensive and defensive weapons because of some of the extremely deep cuts they were able to inflict. Which explains why there are a lot of old laws on the books making it illegal to carry a straight razor in many major cities across the USA. Here in Kansas City where I was living they did indeed still have such a law on the books because KC was one of the big cities that had a lot of mob violence back in the day.

Personally I would be far more afraid of getting attacked with a Straight Razor than I would a knife for those reasons. I've heard many stories of the horrors that straight razors can inflict and they are among the worst I can assure you. Now that is strictly from a weapons standpoint but there is a reason they were using them for weapons when they could have had anything they wanted to use.

My own observation about hollow grinds is that I'm sure they are not nearly as strong as a full flat grind. Just looking at the mere geometry would bear that out IMO.

[Sjucaveman]

I beg to respectfully differ with your take on straight razors. Many of the gangsters and thugs in the day preferred straight razors as offensive and defensive weapons because of some of the extremely deep cuts they were able to inflict. Which explains why there are a lot of old laws on the books making it illegal to carry a straight razor in many major cities across the USA. Here in Kansas City where I was living they did indeed still have such a law on the books because KC was one of the big cities that had a lot of mob violence back in the day.

Personally I would be far more afraid of getting attacked with a Straight Razor than I would a knife for those reasons. I've heard many stories of the horrors that straight razors can inflict and they are among the worst I can assure you. Now that is strictly from a weapons standpoint but there is a reason they were using them for weapons when they could have had anything they wanted to use.

My own observation about hollow grinds is that I'm sure they are not nearly as strong as a full flat grind. Just looking at the mere geometry would bear that out IMO.

Human flesh doesn't bind though as he was saying. Flesh tends to open up when cut so sure straight razors will make large gashes.

[Evil D]

Joe, does it really take good blade geometry to cut a person? I would classify skin/fat/muscle as things that separate fairly easily. I would say those old thugs used straight razors because they were readily available and easy to conceal.

[JD Spydo]

Joe, does it really take good blade geometry to cut a person? I would classify skin/fat/muscle as things that separate fairly easily. I would say those old thugs used straight razors because they were readily available and easy to conceal.

Yeah the more I think about it you probably have a point. It is curious however that so many of those guys were obsessed with using straight razors as offensive and defensive weapons. But with all that is out there today I kind of doubt if they would do now a days with all that is offered.

But all the older AUS-8 Catchermans I had were hollow grind and those older AUS-8 Catchermans were considered so good that back around 2005-2006 I had 2 military guys that were active here on the forum ask me where they could get those older AUS-8 units at the same time the newer MBS-26 Catcherman models had been released. At the time both types of Catcherman models were fairly easy to obtain. But they both insisted on the older hollow grind units and that has had me wondering for some time what the benefit must be with those hollow grind models?

Also the Ayoob model being a hollow grind now has me curious too. Because when Spyderville resident "Doc Snubnose" did his meat test on the Spyderedged version of the C-60 Ayoob he said it performed better than any serrated model he had tested up to that time. And I haven't heard Doc Snubnose ever say that he found any model that was better since that time. Doc was also a fan of the original C-54 big Calypso and I'm sure he had one of the Spyderedged versions at one time which is a full flat grind. I put a lot of trust in everything Doc Snubnose always said because he is a very smart and reputable guy. I wish he would come back and start posting again. I haven't seen him here in about 6 months or so.

What I'm saying is that the hollow grind Spyderedges have indeed performed very well in some of these controlled tests. But on the other hand when you discovered how good the full flat grinds were in SE I tested one for myself and they do very well in FFG in SE. I'm now wondering if the serration pattern itself isn't a bigger factor?

[Evil D]

I just don't see where blade grind makes much difference in meat tests. If you look into medieval sword design there were claymores that barely had an edge on them and they'd still lop a guy's arm off just as easily as a katana. When you're swinging a blade into meat, bad things happen no matter what the blade is shaped like, and in the case of an Ayoob or Yojimbo that has a blade shape that enhances the leverage of a slash, that damage is even worse and I really don't think blade grind has as much to do with it as blade shape and blade angle do. Bodies in general (human/animal) are really pretty fragile, one of the worst cuts I've ever received was from a butter knife that didn't have an actual edge but the force behind the blade sent it through my finger like a razor blade.

The Catcherman is also a very thin blade...one of the thinnest Spyderco have produced in a full sized folder if I'm not mistaken? At 2mm I'm betting you could leave the sides of the blade completely unground and just grind an edge bevel into it and it will do just as much damage to a side of beef. However, that same blade wouldn't slice through rigid materials very well.

Another issue I have with hollow grind is "wandering cuts". On several occasions I've had hollow grind blades "steer" through a cut, even going so far as to almost zig zag left and right. This was a major problem with my original 154CM Manix 2 that was hollow ground and ultimately the primary reason I got rid of it because it annoyed me to no end. I've had similar issues with the Yojimbo 2. So far my Autonomy hasn't been THAT bad, but to be fair I also don't cut near as much cardboard as I did back then so it's less of an issue since I don't cut those types of things as often. The Autonomy is also thinner than either of those blades were.

And to be fair, I've had plenty of wedging issues with FFG as well. Like I said, geometry is inescapable, there's just no way of getting around the fact that you're trying to force a 4mm wedge shaped object through another rigid object. Thinner will always perform better even if your 4mm blade is hollow ground all the way down to a zero grind and the edge is as thin as paper, you still have to push that 4mm spine through what you're cutting and it will eventually bind up if you're cutting something that's deeper/wider/longer than the blade is tall. That 4mm or whatever the blade thickness is will always be a bottle neck and if all other things were equal the same blade in 2mm will perform significantly better regardless of the grind.