which grind for double egded knife

Son of Triglav

Son of Triglav

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Hello,
I'm interested which type of grind works best for a double edged knife and its cutting ability. It appears that almost all(actually I don't know for any which isn't) double edged knives are hollow ground nowadays. Does such prevalence of hollow ground double edged knives mean that this is the most suitable type of grind for a double edged knife? What about convex ground (a.k.a moran grind) or flat ground double edged knife?
 
I go with a flat grind, and a thick edge. It's stronger that way.
the 3/16" blood groove helps too. I like strong.

2001981470194610119521.jpg
 
Thank you for reply (and for the picture). Impressive looking blade.It looks it could also hack pretty well. Who made it?
Flat grind with a thick edge is strong, however a thick edge decreases cutting ability. Wouldn't a convex(moran) type of grind (=strenght and sharpness) be better choice?
 
There are as many opinions on this as there are knifemakers and knife buyers. Here's my view.

I find that a hollow grind, especially one done on a small contact wheel which provides deep hollows, allows me to develop a fine cutting edge in a narrower space while leaving the center of the grind thicker, and therefore stronger.

Here's an example where the top edge was ground with a 2" diameter contact wheel that allowed the very narrow top edge to be fully sharpened all the way to the point. Why make the top edge so narrow? Because it allows the primary edge to be fully developed for heavier and more efficient cutting. That's my take on this anyway.

hossom_fighter.jpg
 
Son of Triglav,

JungleJim made that blade himself!

As Jerry stated, there a zillion ways of doing things, and it depends on what your uses are. Jerry's blades are a martial artist's dream. Jim makes blades for war and has adapted this style to a dagger profile. I bet that thick dagger of his would bite quite hard.

I look forward to the day I can replace my Sears 2X42 with a good 2X72 with contact wheels, so I can make "Awesome Hossom" grinds myself!
 
This knife was designed specifically for military use. Called "Retribution" it uses the deep hollows to remove weight while developing useful edges both at the top and bottom. It also allows the full 3/16" thickness of the steel to run to within 1-1/2" of the point, keeping the blade strong. (BTW, serration's weaken the blade and are only used if needed.) The knife weighs 10 oz and is 13" OAL, with the balance point on the forefinger.

All that said, as with any knife, all that matters is what someone wants to hold in their hand. In that respect my knives are just one alternative among a great many other fine knives.

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(For the record I am not accepting orders so these pix are simply for illustrating the discussion, not for selling.)

Crayola, it's just a matter of time. When you're ready to crank it up, just give me a call. I'm glad to share...
 
Thinner edge thickness can mean more cutting of "soft" material. Thicker edges mean you can chop on rebar, and still have a working edge. Flat grinds are stronger than hollow, simply because there is more steel. Convex is stronger than flat, because of same. A lot of people don't like convex because I hits like a ax (or wedge) instead of cutting deeper.Depending on the thickness of the blade.

I normally go for strength for heavy work.

It all depends on what it will be used for. Is there a possibility it will be used for heavy chores, or only "light" cutting uses.

Nothing does everything great. There are always trade offs.
 
Mr.Hossom, thank you for your reply.I appreciated it. I'm sure there are as many opinions as there is knife makers/ buyers, but I suppose all aren't correct regarding what combat, fighting knife should be like,more or less. Could you tell me what do you think would be the best grind for a dagger or stilleto style double edge knife,that's where both grinds are of the same width?

Crayola, thanks for the clarification. I should have known it was made by JungleJim by the way he replied. Unfortunately, sometimes, I don't read sentences carefully. Junglejim308 ,my apologies.
Regarding my remark on a thick edge, I wasn't particularly questioning JungleJim's knife's ability to cut , I meant that for (mostly production) thick edged flat (or hollow ,for that matter) ground blades in general. I am quite convinced that JungleJim's knife would serve its intended purpose pretty well.

Junglejim308 , you are right. It's what you want it to do- thinner edge thickness means better cutting of "soft" material -like cutting flesh. I had this purpose of a double edged knife (like a dagger) in my mind when I wrote that remark on edge thickness. btw what's the blade thickness of your knife ?
Also could I ask you how does your double edged knife perform at stabbing,piercing? Is there significant resistance because it has so broad point and blade?
 
For the reasons I've given I use the same grind on stilettos. I believe maintaining maximum thickness as far out on the blade as posssible is important for strength. It isn't important how thick a blade is to start with or how heavy it is at the handle, as it is that the blade is strong nearer the point where it will be most highly stressed. Narrower blades are more susceptible to lateral stress. There are also geometric reasons why the hollow grind offers strength in the absence of mass, using the same principle as an arch.

If you were to use that stiletto to chop wood however, it would suck for all those same reasons.
 
Unless I'm making a neck knife or somebody's special order I always use 1/4 inch thick ATS-34, sometimes 440-C.

This dagger penetrates a ammo can easy enough. It'll go past the start of the blood groove.

I didn't think Jerry and me would be the only makers getting in on this. Jerry, keep up the great work!!
 
You keep up the fine work as well. I'm also surprised by the response (or lack thereof). I guess some are afraid to get in the middle of what might be controversial. I think we've shown it doesn't need to be. Where knives are concerned there are plenty of opinions to go around, and none are completely right...
 
Thank you very much both, for presenting your respective views. I expected there would be somewhat more people interested in this particular matter,but nevertheless, it was informative for me.
 
In light of Mr. Hossom's characteristic modesty, I'd like to take the liberty to point out that a "hollow grind" that emanates from Jerry's shop is not always necessarily as simple as it might appear to be on the surface. Anyone who's had the pleasure of owning or using one of these blades, knows well that Jerry goes to great lengths to ensure that any knife he produces is well suited for its intended purpose. Nowhere is this truer than where the blade grind is concerned.

So, while Jerry may simply state that blade A was hollow ground, I can assure you that his skills are such that the exact thickness of the blade in question is precisely controlled at every point across its width, and that his imagination is in no way limited by the diameter of a particular contact wheel.

The point of all of this is simply to say that while JungleJim may be a fan of flat grinds, and Jerry might be a fan of hollow grinds, the skills that these makers possess today are such that these labels don't always tell 100% of the story as to what these blades are actually capable of accomplishing and enduring. Thus it's important to spend a little time actually talking with a custom maker before making any assumptions regarding his or her particular grind style.
 
Thanks Bronco, that's nice of you to say that. The fact is blade grinds are more like sculpture than precision machining, so the variables are almost infinite, apply to all three dimensions, with the edge and its marriage to the grind being yet another set of variables. Hey, it's what gets me up in the morning. :)
 
Personally I think any grind can be and is used on double edged knives. I have seen flat, hollow and convex grinds and have liked most of what I have seen of all three.

I think that usually the grind used is a preference that the maker has. One that he is comfortable with and personally likes the way it looks, though I have talked to some makers that offer their knives with a choice of different grinds. I have seen many that offer both flat or hollow. Not as many it seems offer convex grinds as a choice to the customer. I am not sure if that is because it is a more difficult grind to do, or whether it is because the maker just doesn't like it. I would tend to think it may be a bit of both.
 
I made a convex ground bowie about 7 years ago, it was prefect. I about had to give it away. The people that looked at it thought I couldn't grind flat. They had never heard of convex, and thought I was lying! :rolleyes:
 
Sorry to see that you ran into such a bunch of knowledgable people. It makes one wonder as to why at least some of these people didn't know what a convex grind was. It is not like makers started doing convex grinds just recently. :rolleyes:
 
Beauty is in the eye of the beholder, or in this case the buyer. Convex grinds, for all their merit, tend to be identified with older cheap knives. They are out of fashion, except among the more knowledgeable users, many of whom frequent these forums and have learned of their advantages here.
 
It's all a matter of space. If you make your double-edge blade twice the width of your favorite single-edge blade your blade geometry options are similar. This is seldom the case. It is common for a dagger blade to be narrower than a single-edged blade and so the blade bevel is much more obtuse for a given blade thickness. This means that it is a lot harder to slash with a typical dagger if you don't do something to reduce the edge bevel.

I have found the performance of a typical dagger to greatly improve if I hollow grind the blade. This even worked well on stilletos with blade widths around 1/2-inch.
 
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