History of the Hollow Grind?

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pinnah

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My observation is that most old pocket knives are flat ground and most old fixed blades (40s to 60s) that I see are either flat or sabre/convex ground.

When did the hollow grind become popular?

Was there a corresponding change in manufacturing tooling as plants became more mechanized during the 60s and 80s that allowed the hollow grind to become more common?
 
I believe that the technique of hollow-grinding was first invented by a Sheffield feller for razors. However, Sheffield razor makers were slow to run with it, and it was German razor manufacturers who became famous for hollow-ground razors, with the Sheffield manufacturers only making them later. I imagine that the technique for hollow-grinding knife blades came from razors, but I'm just guessing there.

Interesting thread as always Pete :thumbup:
 
Pretty sure hollow grinds were used on swords long before pocket knives.
 
Hollow ground swords? I don't know if I've ever seen this. I've seen a full-length fuller but I thought the bevels were either flat or convex.

I believe many of the WWII fixed blades were hollow ground and of course the Buck 110 was a very successful hollow ground knife from half a century ago.

I believe most all hollow grinders grind both sides of the blade at the same time which if course requires some pretty precise machinery but also helps prevent missground and bent blades.
 
Any idea when the dual side hollow grinders became common in knife manufacturing?

When did Case start using a hollow grind?
 
I would naively guess the main reason is ease of large volume production and not performance since hollow grind yields weaker/thinner edge than a convex grind (unless a large secondary edge bevel is applied - which is often the case), is not particularly suitable for slicing and it is not quite possible to maintain by end user over the lifetime of the blade and has advantages only in special applications - straight razors are a good example.
 
To throw a little wrench into this, not meant to hijack of course, but I notice almost all of my custom slipjoints and a few custom fixed blades are hollow ground...what's the theory or reason behind this?
 
Jsega51 said:
To throw a little wrench into this, not meant to hijack of course, but I notice almost all of my custom slipjoints and a few custom fixed blades are hollow ground...what's the theory or reason behind this?
Click to expand...

The wheel - Flat grind is done on a flat type belt.
Makers now days as in the past are using very large wheels to grind with.
And when you use a wheel 14'' or larger to grind a slip joint blade, they come very close as if you flat ground them.

I think it's a lot easier to set up a wheel type grind, than it would be a flat grind?
I'm talking more about the past - like late 1800's - early 1900's

Just my thinking.:)

11667273_970509579667200_7097408819662911215_n.jpg

11536052_10206175913910303_3681664848354960259_n_zpsvsc9n7xk.jpg
 
Al,

Thanks so much for posting these pictures. It really helps.

Any idea what sort of grinder is used to produce the hollow grind we so commonly see today? More to the point, any idea when that sort of grinder replaced the large grinding wheels like the ones in the pictures you linked to?

My great-great-great something or others had a small knife/axe/shovel factory in northern VT in the late 1800s. It was powered by waterwheel and all of the knives we have in the family are flat or flat/convex in grind. These are simple rat-tail tang in wood handle affairs but they take a keen edge.

G H Mann knives by Pinnah, on Flickr

Seeing the large radius grinding wheels in the pictures helps me understand them better. Thanks for pointing me to Jack's great thread!!
 
I had a few knives hollow-ground back in the early 90's. They were done on a wheel by hand, feller took but a few minutes and did a great job :thumbup:
 
Seeing all those cool old photos above I would only add that with those large grinding wheels it is also possible to create concave grind via "rocking" the blade. T ishat how the Windmuehle knives from Soligen are still being ground. I do have to add that at the video I have seen they use side of the grinding wheel.
 
do you mean convex? Yes flat and convex grinds could be achieved with a wheel, and just trued with stones... grinding with a wheel is not necessarily the same as impressing its shape in the steel as it were a die.
 
The earliest process I have read about that used hollow grinding was Japanese that used massive natural wetstones to do their grinding on. To the point where their hollow grinds appear flat.

The reasoning is quite simple and even the romans used it. Natural stones were used and it is easier to form a natural stone to a semi circle to run on a axle.

As to our traditional pocket knives. This threas is quite interesting thus far.
 
I was unclear in my first post.

I understand that the old large grinding wheels could produce a shallow hollow (concave) grind - one that could even appear to be flat.

I'm interested in the development of the more severe and pronounced hollow grind like we see on some Case and nearly all Buck knives, among many others.

Am I correct that this sort of grind only became possible in mass production with the advent of smaller grinding wheels, which in turn became possible with the availability of high speed electric motors? This would have started during WW2 and then trickled out to knife makers during the 50s and 60s, no?
 
Maybe somebody in the Buck forum knows why Buck switched the 300s from flat to hollow grind. That might be a clue.
 
The flat ground 300s were made under contract, first by Schrade and later by Camillus. Buck had already switched to a pronounced hollow grind on the 100 fixed blades and the 110.

For that matter, Schrade had also moved to a pronounced hollow grind on many of its knives too.
 
pinnah said:
I was unclear in my first post.

I understand that the old large grinding wheels could produce a shallow hollow (concave) grind - one that could even appear to be flat.

I'm interested in the development of the more severe and pronounced hollow grind like we see on some Case and nearly all Buck knives, among many others.

Am I correct that this sort of grind only became possible in mass production with the advent of smaller grinding wheels, which in turn became possible with the availability of high speed electric motors? This would have started during WW2 and then trickled out to knife makers during the 50s and 60s, no?
Click to expand...

I'm not sure exactly how small an old razor-grinders wheel was, but they were smaller than a knife-grinder's wheel, and used to produce deeply hollow-ground razors before the introduction of electric motors. So perhaps it wasn't that deeply hollow-ground blades couldn't be produced, but just that there was little or no demand for that kind of blade, or at least that was the assumption. It should be said of course that the Sheffield manufacturers and grinders could be deeply suspicious of new technology, and new designs and techniques, and reluctant to change their ways, certainly when they couldn't see an advantage in it.
 
Some more good reading on knives can be found here......

http://www.bladeforums.com/forums/showthread.php/1234135-Brief-History-of-Pocket-Knives


1742 - Sheffield clockmaker Benjamin Huntsman invented crucible cast steel, the first modern cutlery blade steel.

Prior to 1903 factory knives were hand made by single craftsman called "cutlers"

After 1903 the "Hemming grinder" (first automatic grinder) was introduced and knives started being mass-produced.

1907 the "Heroult" electric furnace came into play.

1913 - Around this time stainless steel was in vented.

http://www.bladeforums.com/forums/showthread.php/1118349-Custom-Knife-History
 
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