History of the Hollow Grind?

[Jack Black]

It's off-topic, but I'd have to question some of those dates I'm afraid Al. The occupation of grinder (as distinct from cutler) became established in Sheffield as early as the beginning of the 18th century.

Stainless steel was invented in 1913 :thumbup:

 

[Clem Kadiddlehopper]

Thanks Jack,

"Hemming grinder'' was the first automatic - meaning a machine did the grinding. - right?

 

[pinnah]

Al, the links aren't working for me.

 

[Jack Black]

"Hemming grinder'' was the first automatic - meaning a machine did the grinding. - right?

Not sure about that one my friend, we're still waiting for those new-fangled gizmos in Yorkshire?! :thumbup:

 

[Clem Kadiddlehopper]

Al, the links aren't working for me.

Fixed - should work now. :thumbup:

 

[matus]

Maybe somebody in the Buck forum knows why Buck switched the 300s from flat to hollow grind. That might be a clue.

Because most users have little knowledge how to sharpen a knife and/or have poor gear to do that. Hollow grind makes it (until not too much of material was removed, than you need to re-profile the knife completely, but most knives will never get that far) easier to just touch-up the edge without the edge getting thicker too fast. This approach was further perfectioned by CRK (watch the videos about their knives on youtube for more details). With convex and flat grind you will need to start to thin the knife relatively soon to keep the same blade geometry and requires skill and tools.

 

[Clem Kadiddlehopper]

Not sure about that one my friend, we're still waiting for those new-fangled gizmos in Yorkshire?! :thumbup:

You guys still use something like this?

 

[knarfeng]

Maybe somebody in the Buck forum knows why Buck switched the 300s from flat to hollow grind. That might be a clue.

The 300's were switched to a specific blade profile after a research effort on the part of Buck in the late 90's to develop a blade shape with superior edge retention. They bought a CATRA machine for this effort.
http://www.catra.org/pages/products/kniveslevel1/slt.htm

The result of that effort was called "Edge 2000". It is a super hollow grind and does give superior results on a CATRA machine. (In real life, too.)

As a demonstration, Buck made a blade in BG-42 using their old blade profile. (BG-42 is the supreme melt alloy and gives exceptional edge retention performance that is similar to CPM S30V). They compared the performance of the BG-42 old profile blade to that of 420HC made into a blade of the new profile. The 420HC new profile outperformed the BG-42 blade old profile.

Here is the thread from 2001 made by CJ Buck himself talking about the work. Unfortunately, the graphs no longer show. The links have been broken.
http://www.bladeforums.com/forums/showthread.php/127499-CATRA-Edge-Testing-Results

 

[pinnah]

The 300's were switched to a specific blade profile after a research effort on the part of Buck in the late 90's to develop a blade shape with superior edge retention. They bought a CATRA machine for this effort.
http://www.catra.org/pages/products/kniveslevel1/slt.htm

The result of that effort was called "Edge 2000". It is a super hollow grind and does give superior results on a CATRA machine. (In real life, too.)

As a demonstration, Buck made a blade in BG-42 using their old blade profile. (BG-42 is the supreme melt alloy and gives exceptional edge retention performance that is similar to CPM S30V). They compared the performance of the BG-42 old profile blade to that of 420HC made into a blade of the new profile. The 420HC new profile outperformed the BG-42 blade old profile.

Here is the thread from 2001 made by CJ Buck himself talking about the work. Unfortunately, the graphs no longer show. The links have been broken.
http://www.bladeforums.com/forums/showthread.php/127499-CATRA-Edge-Testing-Results

Frank, just to clarify... the switch to the Edge 2000 geometry happened well after Buck took over production of the 300s from Camillus (1985ish?).

Also, Buck was using a deep, pronounced hollow grind on the 110, 112 and 100 series long before either of these things.

What I'm trying to figure/find out is when the deep, pronounced hollow grind (as opposed to a shallow, almost flat hollow grind) first started to gain popularity and what, if any, manufacturing changes allowed that to happen.

The guys in the Schrade forum pointed out that Schrade had "Kon Kav" ground knives right after WW2. But then Schrade had a lot more starting in the late 70s (e.g. LB7, 6OT).

What I'm wondering is if there were advances in automation that allowed for a double wheel grinder to consistently and quicly produce deep hollow grinds and if so, when did that happen? I have a hunch this is tied to greater availability of electrical motors post-WW2 and with that, the possiblity of driving smaller radius grinding wheels at consistent and high speeds.

 

[knarfeng]

I answered a specific question. The change on the Buck 300 series from a flat grind to a "hollow grind" occurred in the very late nineties, after 1997.

 

[Jack Black]

You guys still use something like this?

:thumbup:

Here is the thread from 2001 made by CJ Buck himself talking about the work. Unfortunately, the graphs no longer show. The links have been broken.
http://www.bladeforums.com/forums/showthread.php/127499-CATRA-Edge-Testing-Results

Interesting link Frank :thumbup:

 

[pinnah]

I answered a specific question. The change on the Buck 300 series from a flat grind to a "hollow grind" occurred in the very late nineties, after 1997.

Frank,

Thanks for clarification on this point and have every reason to believe you're 100% correct on this. It had been my recollection based on something I (perhaps mistakenly) recall Craig (aka 300Bucks) say in the Buck forum that hollow vs flat ground was a good indicator of whether a (pre-off shore contracting) 300 series knife was made by Buck or by Schrade or Camillus.

By luck, Craig's great post on the history of the 300 series resurfaced on the Buck forum and so I've asked Craig for clarification. But again, I believe you are 100% right on this.

Thanks,

Dave

 

[pinnah]

When did Case start using a deep hollow grind on their pocket knives?

 

[knarfeng]

I have a '92 Buck 301 and a '97 Buck 303, both with flat ground blades, and both stamped "USA", if that helps answer your question.

 

[screened porch]

The 300's were switched to a specific blade profile after a research effort on the part of Buck in the late 90's to develop a blade shape with superior edge retention. They bought a CATRA machine for this effort.
http://www.catra.org/pages/products/kniveslevel1/slt.htm

The result of that effort was called "Edge 2000". It is a super hollow grind and does give superior results on a CATRA machine. (In real life, too.)

As a demonstration, Buck made a blade in BG-42 using their old blade profile. (BG-42 is the supreme melt alloy and gives exceptional edge retention performance that is similar to CPM S30V). They compared the performance of the BG-42 old profile blade to that of 420HC made into a blade of the new profile. The 420HC new profile outperformed the BG-42 blade old profile.

Here is the thread from 2001 made by CJ Buck himself talking about the work. Unfortunately, the graphs no longer show. The links have been broken.
http://www.bladeforums.com/forums/showthread.php/127499-CATRA-Edge-Testing-Results

Thanks, Frank. Stout fellows, those Bucks, switching to something that cuts better instead of something that's cheaper to make.

 

[pinnah]

I have a '92 Buck 301 and a '97 Buck 303, both with flat ground blades, and both stamped "USA", if that helps answer your question.

Frank, yes it helps considerably as it puts the final nail in the coffin of my confusion on when the 300s went to a hollow grind. I definitely misremembered.


My deeper question is still unanswered.

I'm really wondering if advances in automation technologies allowed for cheaper mass production of deep hollow grinds and if so, when that took place.

In cycling, we saw advances in automation drive huge differences in bike frames. This was primarily in the 70s through the 90s.

It occurs to me that this appears (to me) to be about the time that deep hollow grinds became more commonplace and I'm wondering if improvements in production moved the hollow grind from the realm of more expensive hand production to less expensive automated grinding.

 

[stezann]

the only grinding relevant cost is into abrasive. For a flat grinding machine, if any, there is an increased energy consumption, since the necessary belt drag you get on the flat plate. A wheel on bearings, Vs. 2 wheels + platen cuts costs.

I find deep hollow grinds just ugly and ineffective for knives saving straight razors of course....but that's just for another thread maybe.

 

[Temujin H-Pinchers]

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.

Back in the 19th century razors weren't as hollow as they became at the turn of the 20th century. Razors would have been ground, by hand, on wheels anywhere from 6 to 12 inches, a 6 inch wheel in the 19th century was considered very hollow at that time and you occasionally see razors etched with 'Ground on a X inch wheel' I suppose as a selling point. In 1893 a machine was created in Gemany called the Hexe, developed by Carl Friedrich Ern which was a double hollow grinder (both sides of the razor at once) Only then did it become possible to get the extremely thin and hollow razors that are still produced today (wheels as small as 2 inches in diameter). I imagine this technology is what made it's way into the knife world.