Hollow Grinds

[Cambertree]

I like the Gayle Bradley 1 blade grind a lot.

[James Y]

I like tall hollow grinds best. I normally dislike short hollow grinds, but they’re not so bad on the Seki Salts; I can see why they are short and fairly abrupt, due to their purposes. But I only like those in SE.

IMO, a high hollow grind like CRK uses would be optimal. The issue I have with CRK’s hollow grind is their insistence on pairing it with relatively thick convex edge bevels, which kind of cancels out the benefits of the high HG. Oftentimes, the edge bevels need to be reprofiled.

As has already been mentioned, the HG on the Yojimbo 2 looks amazing; it’s a knife I may be interested in getting someday.

I have some doubts that a really high HG on a Spyderco would go very well with SE on most models. I think of it being better with PE. Although my Dragonfly Salt, which has a high HG and SE, is fine.

Jim

[Cambertree]

Probably an opportune time to bring this up again, from the Afi Performance Flash Batch thread last year.

The discussion was about a more thinly ground, high performance model.

My recollection is that there was some discussion about potential steels, and at the time we were waiting for Bohler to do another melt of K390. Other Japanese steels and AEB-L and 52100 were suggested too IIRC. A full height hollow grind would be pretty cool, combined with a thin behind the edge width.

The Delica is the current plan. I've got a drawing, now to see if the maker can get to the odd specs. Very thin edge, high hollow grind, high hardness steel, etc.

sal

viewtopic.php?f=2&t=79799&hilit=Hollow&start=180

[emanuel]

It depends on a hollow grind.
I would like to see hollow Grind as done on Sebenza, like a true hollow grind, where the edge it a bit thicker and then gets thinner. But you can also make it more like a flat grind, where it gets thicker right away


I hope this picture make sence....

Like, I have no idea how is hollow grind done on mass production, but I have a feeling that it is not that easy (togehter with convex grind).
Hollow grind on H1 salt should be done with two wheels on both sides, but that leaves the tip quite thin and it would look from above on tip, it is hollow.
Hollow grind on like a Gayle Bradley 2 is done different, but I have no idea how they made it.

I know exactly what you mean. I love my straight razors in that grind, its called "double concave bellied hollow/bellied hollow". They sing like nothing else when shaving, similar with extra full hollow grinds, but those obviously wouldn't be good for knives lol. A bellied hollow? **** yea, especially if enough thickness is given to the thinner side of the grind wall. One big advantage is that sharpening doesn't particularly increase the thickness behind the edge that much, even decreasing towards the end of the razor's/knife's lifetime.

[Cambertree]

I know exactly what you mean. I love my straight razors in that grind, its called "double concave bellied hollow/bellied hollow". They sing like nothing else when shaving, similar with extra full hollow grinds, but those obviously wouldn't be good for knives lol. A bellied hollow? **** yea, especially if enough thickness is given to the thinner side of the grind wall. One big advantage is that sharpening doesn't particularly increase the thickness behind the edge that much, even decreasing towards the end of the razor's/knife's lifetime.

Very interesting information Emanuel, thanks.

[Pancake]

Hey emanuel, great pics that lovely illustrated how much difference could be between hollow grinds.

On the other hand, I have my doubts that you could really sharpen knife to its death, like, it gets so thick that is really pain to cut with. Like, if you remove just enough steel, you have a very long time even with FFG blade

[emanuel]

Hey emanuel, great pics that lovely illustrated how much difference could be between hollow grinds.

On the other hand, I have my doubts that you could really sharpen knife to its death, like, it gets so thick that is really pain to cut with. Like, if you remove just enough steel, you have a very long time even with FFG blade

By "death" I wasn't referring to sharpening the knife all the way to the spine lol :D, but until it needs a regrind which for most people that's where everything is done for. A regrind of course can be done but most people don't have the skill to do it not even on ffg blades, let alone a concave hollow, or just prefer to buy a new knife completely if its low-mid range, instead of paying the same price to a smith to do the regrind (it ain't cheap). Taking razors as examples, its done free hand on two wheels both pushing outward on the blade, and not over-grinding it and putting a hole in the middle of your blade is done purely by eye and experience.

I also believe it can't be done with a jig on a belt sander using a smaller diameter wheel on one of its corners, but what was said above is the "old-school" way.

[Pancake]

Thank you, some really cool informations.
I started wet shaving with straight razor, but then I switched to DE razor.
Still, I love how straight razor looks.

[emanuel]

Thank you, some really cool informations.
I started wet shaving with straight razor, but then I switched to DE razor.
Still, I love how straight razor looks.

I got my straight razor love from my grandpa almost 15 years ago when I was barely having a crappy teenager half-mustache fluff going on lol (he gave me a Stiz Paketa - to be read "Racketa", a homage from the start of the soviet space race, probably made somewhere in early 1960s), but in my day to day I use a DE razor too except in the weekend when for once I can take my time and get a proper straight razor shave. My favorite users atm is a CV Heljestrand MK10 (half hollow) and MK32 (full hollow) - the last one is pre-1939 since that's when they stopped using ivory for handles so I don't think I'll ever sell it especially knowing how little I paid for it at the time. I also have a Filarmonica 14 and that's it. My knife hobby eats enough of my money I try to avoid spending too much time on ebay looking at straights, but I can't pass good deals :rolleyes: Too bad the prices exploded lately on quality vintage razors.

Back to knives, I would love a bellied hollow Spyderco, like someone else said I like how Sebenza has done it. Too bad it's not higher ground and the handle is a broomstick ergonomically :D Pls don't hate on me guys!
P.S. I was just imagining a blade like on the Kapara in that geometry. Wew! Laser for shallow cutting. I need to stop torturing myself.

[Bill1170]

When honing a straight razor on a stone, the edge bevel is self-jigging because you lay the blade onto the stone with the edge and the spine both touching the stone. The hollow grind makes this possible.

[amateur blacksmith]

Thanks for the segue into hollow grind straight razors Emanuel. Fascinating stuff, those blades must be almost paper thin. And done by eye too.

There seems to be some love for the Sebenza grind and I agree. Although for me the absent knife in question needn't be a clip point necessarily although that's OK with me. The GB no doubt is very good, but sort of misses the brief as I see it as a gentleman's folder with it's smoother scales.

A large (3.5-4") grippy durable folder, tall hollow grind. And a liner of frame lock. (thought I'd add my lock preference for good measure) Most people don't hard use their knives cutting through car door and whittling steel tent pegs. Never heard anybody saying their HG Sebenza doesn't cut the mustard as far as durability goes.

[ronT2]

Back to knives, I would love a bellied hollow Spyderco, like someone else said I like how Sebenza has done it. Too bad it's not higher ground and the handle is a broomstick ergonomically :D Pls don't hate on me guys!
P.S. I was just imagining a blade like on the Kapara in that geometry. Wew! Laser for shallow cutting. I need to stop torturing myself.

Emanuel, thanks for the interesting post. I had no idea there were that many variations of hollow ground straight razors.

If this became a reality, I would have one for sure. I've been thinking about a hollow ground Kapara for a while.

Even though the GB2 has a high hollow grind, I still found that knife to be one of the worst slicers I had. It also had an extremely small bevel on such a nice blade. I'm sure that's another factor in it's lack of great slicing though. Now that I'm much better at sharpening and reprofiling...I wish I didn't give up on it and sell it.

Does anybody else have a GB2 that can relate to the barely there bevel, or did I just happen to land a dud?

I can relate to the barely there edge bevel, but not to selling a GB2. :D

I have four hollow ground Spydies, one GB1, two GB2s and a Lil Sub Hilt. They all have a behind the edge thickness of about .015”. So, at .007-.008” per side that doesn’t leave much stock for a factory edge bevel @ 40-degrees. About .5 millimeter or .020” is all the bevel you’re going to see from the factory.

[Cycletroll]

Count me in on favoring a high hollow grind. I've been carrying and using a Sebenza a lot lately and continue to be more and more impressed with what a great performing knife it is! Personally I'm kind of tired of FFG.
If I had to choose one pocket knife it would be a high hollow.
TkoK39SPY,
IME the GB2 is a good performer. Not quite as ideal as the GB1. Both of my GB1'S are very thin BTE (.015&.018 respectively). I prefer the handle shape and the stouter liner on the GB1 as well.
A Cruwear GB1 could very well be the perfect pocket knife for me as I use the M4 version a ton and the added corrosion resistance with decent toughnessof Cruwear would fit its personality as a work knife.
Sorry about the ramble; I got off on a tangent thinking about hollow ground knives I like

[Cycletroll]

Current favorite EDC knives:
Hollow Ground:
Sebenza 21
Gayle Bradley1
Demko AD10
Pacific Salt PE
Tuff (still feeling this one out:)
FFG:
Endura (SG2 or S30v)
Mille (204p or s90v)
PM2 (have lots of steel variants but find i carry the brown s35vn the most)

[Sumdumguy]

It depends on a hollow grind.
I would like to see hollow Grind as done on Sebenza, like a true hollow grind, where the edge it a bit thicker and then gets thinner. But you can also make it more like a flat grind, where it gets thicker right away


I hope this picture make sence....

Like, I have no idea how is hollow grind done on mass production, but I have a feeling that it is not that easy (togehter with convex grind).
Hollow grind on H1 salt should be done with two wheels on both sides, but that leaves the tip quite thin and it would look from above on tip, it is hollow.
Hollow grind on like a Gayle Bradley 2 is done different, but I have no idea how they made it.

I know exactly what you mean. I love my straight razors in that grind, its called "double concave bellied hollow/bellied hollow". They sing like nothing else when shaving, similar with extra full hollow grinds, but those obviously wouldn't be good for knives lol. A bellied hollow? **** yea, especially if enough thickness is given to the thinner side of the grind wall. One big advantage is that sharpening doesn't particularly increase the thickness behind the edge that much, even decreasing towards the end of the razor's/knife's lifetime.

Looking at these pictures, I'd like to see something like a double concave bellied 3/4 hollow on a knife.

[Halfneck]

After a week of fiddling around with my Roadie I think it would be a great candidate for a hollow grind.