Hollow or Flat
- Thread starter Rick Otts
- Start date
J. Hoffman
Dealer - Purveyor
Yes!
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Self Made Knives
Well-Known Member
I tended to like flat grind blades before I started making knives, so naturally, that's what I started out making. Chris Taylor gave me a lesson on hollow grinding and I'm still not that great at it. I think they are about the same as far as difficulty of grinding. The difference for me is if you have a mistake or not quite flat, etc. It's not that hard to fix a little issue on a flat ground blade with plenty of hand sanding. Hollow grinds, however, they need to be pretty much perfect off the grinder. I think you should practice both and become equally as skilled in each.
John Wilson
Well-Known Member
I like flat grinding for all the reasons Anthony says. Another reason is because I really like that hand rubbed finish, and honestly I don't know how to get that on a hollow ground knife. I'm not even sure it would be desirable. A hollow ground knife just look "right" with the vertical grind marks in the hollow, and truth be told it's hard for me to look at grind marks and feel like the knife is finished. I know- it's a totally wackadoo hangup that only exists in my mind. I embrace my craziness.
EdCaffreyMS
"The Montana Bladesmith"
Ok, Ed's gona climb up on his soapbox. 
Each of these are entirely different animals, each with it's own characteristics and it's own +/-. A true hollow grind is two arcs, that start at the spine, and intersect at the edge.... this is a very sharp, thin edged grind, that excels at very fine cutting jobs. The drawback is that the edges on these knives are very delicate when compared to other types of grinds. All of that is assuming that the grind is actually a true hollow grind, and not what I refer to as a (I'll use the term "sorta" hollow grind.) By that I mean what many refer to as a "hollow grind" simply isn't..... these days we generally see a "hollow grind" where there is a slight hollow with a flat portion left towards the spine, with the "hollow" stopping short of the edge...leaving an overly thick edge that folks take down to some overly obtuse angle. This all started back in the late 60s/early 70s when a certain production knife company tried to correct an engineering/design mistake in one of their models....they had initially made the knife with a full flat grind, on a steel that was far too hard for that type of grind....people kept chipping out and/or breaking blades. But rather then rethink the steel, it's hardness, and geometry, they came up with this crazy grind that left the blade's edge super thick and heavy, in order to solve the issue of blades chipping/breaking. What they actually did was create a blade that's more closely related to a cold chisel then a knife. For whatever reason, this caught on with the custom knife world, and the rest is history. You can see this when you look at photos of some custom knives...... smallish hollows on the blade, and a HUGE edge bevel......all it equates to is "built in" cutting resistance. If you're going to do a hollow grind, do it for the right reasons, and with the intent to make it an attribute of the blade, and not just so it looks cool (which usually makes it a hindrance to blade performance). OK....off my soapbox now!
As far as ease, I personally don't have more difficulty with one then the other, however, I rarely ever hollow grind, unless its for a very specific purpose (small kitchen cutlery or razors). When it comes to a flat grind, I rarely do a full one of those either. The reason is that over the years I have studied/learned how to implement geometry into my blades that offer what I consider a good balance of reduced cutting resistance and strength. What I normally do is a combination of a flat grind on most of the blade, then convex the last 1/4" or less of the edge (depending on the blade type/use). Ultimately what I seek to achieve is using the flat grind to reduce weight, which makes a blade feel "faster" and "lighter" in the hand, and the convexed edge portion is there to reduce cutting resistance (I strive for as close to no edge bevels as possible) but because of the couple of extra thousandths in thickness just above the cutting edge, edge strength is increased fairly dramatically versus a full flat grind.
In the end, making something that look cool, but doesn't necessarily preform well, will sell you a few knives.....but people will quickly catch on, and you'll soon wonder why things started out so well, then fall off. If you make something that performs well, often times it will take a while for folks to discover it, but once they do, you generally have customers for the long term.
Each of these are entirely different animals, each with it's own characteristics and it's own +/-. A true hollow grind is two arcs, that start at the spine, and intersect at the edge.... this is a very sharp, thin edged grind, that excels at very fine cutting jobs. The drawback is that the edges on these knives are very delicate when compared to other types of grinds. All of that is assuming that the grind is actually a true hollow grind, and not what I refer to as a (I'll use the term "sorta" hollow grind.) By that I mean what many refer to as a "hollow grind" simply isn't..... these days we generally see a "hollow grind" where there is a slight hollow with a flat portion left towards the spine, with the "hollow" stopping short of the edge...leaving an overly thick edge that folks take down to some overly obtuse angle. This all started back in the late 60s/early 70s when a certain production knife company tried to correct an engineering/design mistake in one of their models....they had initially made the knife with a full flat grind, on a steel that was far too hard for that type of grind....people kept chipping out and/or breaking blades. But rather then rethink the steel, it's hardness, and geometry, they came up with this crazy grind that left the blade's edge super thick and heavy, in order to solve the issue of blades chipping/breaking. What they actually did was create a blade that's more closely related to a cold chisel then a knife. For whatever reason, this caught on with the custom knife world, and the rest is history. You can see this when you look at photos of some custom knives...... smallish hollows on the blade, and a HUGE edge bevel......all it equates to is "built in" cutting resistance. If you're going to do a hollow grind, do it for the right reasons, and with the intent to make it an attribute of the blade, and not just so it looks cool (which usually makes it a hindrance to blade performance). OK....off my soapbox now! As far as ease, I personally don't have more difficulty with one then the other, however, I rarely ever hollow grind, unless its for a very specific purpose (small kitchen cutlery or razors). When it comes to a flat grind, I rarely do a full one of those either. The reason is that over the years I have studied/learned how to implement geometry into my blades that offer what I consider a good balance of reduced cutting resistance and strength. What I normally do is a combination of a flat grind on most of the blade, then convex the last 1/4" or less of the edge (depending on the blade type/use). Ultimately what I seek to achieve is using the flat grind to reduce weight, which makes a blade feel "faster" and "lighter" in the hand, and the convexed edge portion is there to reduce cutting resistance (I strive for as close to no edge bevels as possible) but because of the couple of extra thousandths in thickness just above the cutting edge, edge strength is increased fairly dramatically versus a full flat grind.
In the end, making something that look cool, but doesn't necessarily preform well, will sell you a few knives.....but people will quickly catch on, and you'll soon wonder why things started out so well, then fall off. If you make something that performs well, often times it will take a while for folks to discover it, but once they do, you generally have customers for the long term.
John Wilson
Well-Known Member
which begs the question: why have "hollow grinds" gotten so popular? (concave grinds if you prefer, but everyone here knows what people mean when they say "hollow grind") Is it just what people expect because that's what they get on nearly every production knife from department stores?
We all have our personal preferences. I never understood the typical "hollow grind" on production knives. As soon as you leave that thick edge with a V-grind, the blade is functionally not a hollow grind and loses almost any cutting benefit a real hollow grind would have had. Not only that, but if someone is sharpening on a stone, the edge angle can never be more acute than a true zero flat grind from edge to spine would have been. Unless you are prying, a hollow grind just means you could have used a thinner blade to begin with. But that's just my opinion, and what do I know?
In my books by Loveless, he liked a hollow grind on his knives. I'm sure he had his reasons. It didn't seem to hurt sales, either. At any rate, I think it was a good question to ask, and no reason to cast aspersions on any maker who sees it differently. Just like I don't believe in sharpened pry bars. I don't understand having a blade with a cutting edge that goes 3/8" up the blade. I hate serrated knives. At the end of the day, who gives a flying crap what I like? There are markets for all of these things. A knife only has to satisfy two people: the customer and the maker.
We all have our personal preferences. I never understood the typical "hollow grind" on production knives. As soon as you leave that thick edge with a V-grind, the blade is functionally not a hollow grind and loses almost any cutting benefit a real hollow grind would have had. Not only that, but if someone is sharpening on a stone, the edge angle can never be more acute than a true zero flat grind from edge to spine would have been. Unless you are prying, a hollow grind just means you could have used a thinner blade to begin with. But that's just my opinion, and what do I know?
In my books by Loveless, he liked a hollow grind on his knives. I'm sure he had his reasons. It didn't seem to hurt sales, either. At any rate, I think it was a good question to ask, and no reason to cast aspersions on any maker who sees it differently. Just like I don't believe in sharpened pry bars. I don't understand having a blade with a cutting edge that goes 3/8" up the blade. I hate serrated knives. At the end of the day, who gives a flying crap what I like? There are markets for all of these things. A knife only has to satisfy two people: the customer and the maker.
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Rick Otts
Well-Known Member
You might like serrated blades better if you ever trapped.I find them the best thing going when you get too skinning the head.Besides that I am with you.
John Wilson
Well-Known Member
See? I learned something. There has to be a good reason so many people like certain things. I just hadn't found a personal use for them where I preferred serrations. Now I know what they're good for. My brother in law likes them because he stinks at sharpening knives.
scott.livesey
Dealer - Purveyor
hollow grinds are popular and on most department store production knives because there are automated machines available where you put a hardened blank in one end and a hollow ground, sharpened, and polished knife comes out the other. the blade passes between a series of two contra-rotating stones(left stone goes clockwise, right stone counter-clockwise) and out pops a sharp hollow ground knife.
John Wilson
Well-Known Member
That makes perfect sense.
EdCaffreyMS
"The Montana Bladesmith"
Not only do I agree with Scott, but I'm fairly certain that ever production knife company out there are what I call "bean counters" (from a business aspect, how could they be anything else)...... gotta put as little into a product, and get the most they can out of it. Sadly that means more often then not it's about the bottom line versus the overall quality. I remember a conversation I had with one particular gentleman who was the foreman at a major name production knife company.....the way he put it was...
We produce only the level of quality that the public demands in order to sell a given knife for a given price, and do it in such a manner as to realize the maximum amount of profit.
Personally, I think that's what separates "custom" and production knives. From my viewpoint, a custom maker cannot afford to do less then he/her very best on each knife they build, but that just might be me. I have to admit that it drives me crazy when I have someone ask me "how long did it take to make that knife?" My usual answer is "30+ years", because everything I've learned to this point goes into each one. Also, I'm afraid that if I ever started counting hours, I'd get so depressed that I'd just quit.
Seriously though, I think it's the difference between having a sincere love for the craft versus a purely business mentality.
We produce only the level of quality that the public demands in order to sell a given knife for a given price, and do it in such a manner as to realize the maximum amount of profit.
Personally, I think that's what separates "custom" and production knives. From my viewpoint, a custom maker cannot afford to do less then he/her very best on each knife they build, but that just might be me. I have to admit that it drives me crazy when I have someone ask me "how long did it take to make that knife?" My usual answer is "30+ years", because everything I've learned to this point goes into each one. Also, I'm afraid that if I ever started counting hours, I'd get so depressed that I'd just quit.
Seriously though, I think it's the difference between having a sincere love for the craft versus a purely business mentality.
rhinoknives
Well-Known Member
Hello Ed, Scott, John and others!
Ed,
I agree with your comments about a true Hollow grind completely.
I prefer flat, with just a taste of Convexing at the bottom 1/4-1/3 of a Full Flat Grind.
I've debated having a machinist make an arch Platen that would replicate about an 8 foot, wheel so I could made a full Hollow on one or both sides of my
2 3/4" - 3" at the heel culinary knife patterns.
Maybe someday!
Tell then, I am very happy how my FFG's cut,slice & dice, and the important thing is my customers are happy too!
Ed,
I agree with your comments about a true Hollow grind completely.
I prefer flat, with just a taste of Convexing at the bottom 1/4-1/3 of a Full Flat Grind.
I've debated having a machinist make an arch Platen that would replicate about an 8 foot, wheel so I could made a full Hollow on one or both sides of my
2 3/4" - 3" at the heel culinary knife patterns.
Maybe someday!
Tell then, I am very happy how my FFG's cut,slice & dice, and the important thing is my customers are happy too!
scott.livesey
Dealer - Purveyor
this is why i recommend folks look for handmade knives. the Japanese count beans just like we do, knives from Shun and other large makers are made in automated assembly lines. the pictures of ancient Japanese craftsman making your knife kneeling between an anvil and a charcoal forge are advertising hype 99% of the time.
J. Doyle
Dealer - Purveyor
^^^Excellent quote Ed. I like that a lot!
Quoted for absolute truth.