Spyderco Forums

We all enjoy a knife that slices well. I've often felt is a shame Spyderco don't produce any models with a convex grind. Anyone who's used a knife with this kind of grind will have appreciated its cutting ability for slicing. This is because the nature of the grind means there is very little blade in contact with the material you are cutting through. At the same time the grind provides strength to a thin blade (Opinel excels at this).

I'm aware that given how Spyderco is set up the costs would probably run too high but I would love to have a shallow convex grind in a thin bladed knife like the Chaperral with all of its cool Spydie features (twill carbon fiber, precision made, S30-v, ergo's).

We can dream.... :cool:

I've convexed my current EDC FFG VG10 Endura and the steel does really well convexed. On the other hand extra strength has never been really needed as long as I've not gotten it crazy thin or asked more than I should from the blade.

I've had some at angles like 15 degrees inclusive at times but I've never pushed the thinned ones really hard. For regular stuff the 15-20 degree inclusive presented no problems with VG10.

Joe

Way I see it, slicing ability is inversely proportional to thickness behind the edge and a full flat grind can always be made thinner there than a convex grind.

I've used both grinds on both thick (4mm) and thin (2.5mm) blades. The only advantages I see to a convex grind are that it's a stronger edge because it's a bit thicker and it's a bit easier to touch up in the field. Neither of these is a big concern to me so I prefer the straight bevels that Spyderco uses.

Most of my carry knives are around 3mm at the spine and flat ground. I don't own anything with a thinner blade than 2.5mm so I can't speak to really thin blades with convex grinds. For the knives I carry, the standard Spyderco beveled blade grinds have worked well for me at work, at home, and in the woods, so I'll stick with them

I had heard some years back that the original Spyderco MORAN models were made with "convex edges". Bill Moran from what I heard was supposed to be sort of the grandfather of "convex edges".

It seems like someone told me back around 04 or 05 that the MORAN model fixed blade for the first 2 years were all convex edges from the factory. I never owned any of the first generation MORAN models so I can't say 100% for sure.

But I do remember seeing some of them on Ebay actually advertised with convex edges :confused:

I believe the Hossums are all convexed, as well, but I don't know of any folders that come this way...?

I convexed my military s30v and I like it. It is very easy now to touch up.
Virtuovice has videos on YouTube on how to convex a V-edge.
Start with a cheap knife ☺.
Good luck

JD Spydo wrote:I had heard some years back that the original Spyderco MORAN models were made with "convex edges". Bill Moran from what I heard was supposed to be sort of the grandfather of "convex edges".

It seems like someone told me back around 04 or 05 that the MORAN model fixed blade for the first 2 years were all convex edges from the factory. I never owned any of the first generation MORAN models so I can't say 100% for sure.

But I do remember seeing some of them on Ebay actually advertised with convex edges :confused:

Yes, the first run or runs of Morans were convex. I believe Sal once said they stopped doing it because too few people understood how to sharpen a convex edge properly.

The Deacon wrote:Way I see it, slicing ability is inversely proportional to thickness behind the edge and a full flat grind can always be made thinner there than a convex grind.

I convex my Spydies by thinning them out at the shoulder so they are actually slightly thinner behind the edge. This only works since full flat Spydercos have an edge ground at a higher angle than the rest of the full flat. On a zero ground edge it is like you wrote

My kitchen knives are mostly very thin full convex.

If Spyderco were to switch to full convex I imagine their manufacturing costs would increase quite a bit. Since not too many users want it I don't think we will see it.

Sverre

The Deacon wrote:Way I see it, slicing ability is inversely proportional to thickness behind the edge and a full flat grind can always be made thinner there than a convex grind.

Convexed edges are not done as much because they need to be hand made. So with mass produced knives the costs would go up greatly. This is why you see most with hollow grind or ffg. Im a convex fan, convexed my delica ffg also. And I agree if you want to learn more about this check out virtuovice on youtube, hes the one who got me started on all this. Also check out knivesandstuff, who has a whole series on videos on convex grinds. Convexed edges are the best imo, if done right of course. One company that does this right is Bark River. Anyone who owns a bark river knife knows what Im talking about. Scary sharp and easy to maintain. Cuts through material like a bullet through a cloud.


This is true, but we also need to remember that slicing ablity is effected by resistances put forth by the blade when cutting as well. With a convexed edge, the material is pushed out of the way when cutting. Only the cutting edges touches the material, causing very little resistance. In contrast, although thin, a hollow grind has the material pushing up into the blade, causing greater resistance. Ffg is in the middle, where as the edge is slicing, the material is sliding up the side of the blade instead of being pushed outward away from the rest of the blade like with a convexed edge. This can be easily seen when cutting food in the kitchen. Ever notice food gettig stuck to kitchen knives and almost like its suctioned to the blade. Thats partly because of the flat grind. Imo convex is the best grind out there.

But check out this video for more info.

http://youtu.be/2j8V-Rcyj4s

Drkknight614 wrote:Convexed edges are not done as much because they need to be hand made. So with mass produced knives the costs would go up greatly. This is why you see most with hollow grind or ffg. Im a convex fan, convexed my delica ffg also. And I agree if you want to learn more about this check out virtuovice on youtube, hes the one who got me started on all this. Also check out knivesandstuff, who has a whole series on videos on convex grinds. Convexed edges are the best imo, if done right of course. One company that does this right is Bark River. Anyone who owns a bark river knife knows what Im talking about. Scary sharp and easy to maintain. Cuts through material like a bullet through a cloud.


This is true, but we also need to remember that slicing ablity is effected by resistances put forth by the blade when cutting as well. With a convexed edge, the material is pushed out of the way when cutting. Only the cutting edges touches the material, causing very little resistance. In contrast, although thin, a hollow grind has the material pushing up into the blade, causing greater resistance. Ffg is in the middle, where as the edge is slicing, the material is sliding up the side of the blade instead of being pushed outward away from the rest of the blade like with a convexed edge. This can be easily seen when cutting food in the kitchen. Ever notice food gettig stuck to kitchen knives and almost like its suctioned to the blade. Thats partly because of the flat grind. Imo convex is the best grind out there.

But check out this video for more info.

http://youtu.be/2j8V-Rcyj4s

Bingo! :D

P.S. I'm talking about a full convex grind too, not just the edge bevel (I've tinkered with that too with mixed results!

avoidspam wrote:P.S. I'm talking about a full convex grind too, not just the edge bevel (I've tinkered with that too with mixed results!

i have to agree with that statement. my brkt bravo2 is full convex ground and is amazing, especially considering its large thick blade. it slices as well as thinner ffg blades. my more used spyders and others end up with a convex edge more due to excessive stropping but dont really get the benefit of a full convex grind. ive become a believer in this style of grind for a few reasons that seem to hold true, less resistance or drag cutting threw material, stronger edge, ease of maintaining. i really want to try one in a smaller edc size knife. i dont really think theres much benifit to doing a convex edge on a saber or ffg blade other than some slightly better edge durability and ease of touch up if using a strop.

I have a couple FB01's. One with Gold filled Moran Signature and polished blade. One with Black filled Moran Signature and polished blade. One Krein Reground Moran with full convex blade bevel with convex micro bevel which was added for edge stability.

Nice :)

bada61265 wrote:i have to agree with that statement. my brkt bravo2 is full convex ground and is amazing, especially considering its large thick blade. it slices as well as thinner ffg blades. my more used spyders and others end up with a convex edge more due to excessive stropping but dont really get the benefit of a full convex grind. ive become a believer in this style of grind for a few reasons that seem to hold true, less resistance or drag cutting threw material, stronger edge, ease of maintaining. i really want to try one in a smaller edc size knife. i dont really think theres much benifit to doing a convex edge on a saber or ffg blade other than some slightly better edge durability and ease of touch up if using a strop.

Opinel's don't break the bank and demonstrate what a shallow convex grind on a thin blade can achieve. Couldn't be further (design ethos wise) from a Spyderco. An Opinel no8 Inox shares pretty equal pocket time with my Delica 4 ffg g10. Have recently purchased a Scagel Fruitport, the blade is convexed by Bark River, Very nice. It's quite hard to find production knives with full convex grinds, again probably for the reasons discussed here.

Man are the convex blades easy to maintain and resharpen once done. It took a while convexing my Endura by hand. I did it over a few weeks a half hour at a time but now it's just so easy resharpening it I end up looking for other knives to maintain to get my quota of relaxation time.

I'm not going to convex everything but a couple more are destined for convexing. My first convex edge that I got to know and figured out, liking the performance was a Marbles 52100 ( 1999-2000 range when Mike Stewart was there) that I picked up cheap at a gunshow I was working. I bought it for the 52100 steel and learned to like the convex edge.

I have a few different combinations in convex including both 3V and Infi and I feel it does very well at some things.

No one steel, knife design , size, or grind will ever be my favorite or, hopefully only knife anymore than one tool for every purpose would suffice but there is room and jobs that fit convex edges very well.