How is a "hollow" grind achieved?

Gawker · Jul 5, 2005

I'm not a knife maker. I've never made a knife. I've designed one over the last few months in my head that I would greatly like to see realized to add to my collection. One of the problems I'm having with getting it added to the real world is the fact that I don't have access to a machine shop to do what I want, and I don't have the kind of money it would probably take to have the thing made FOR me to the specs I would like to see.

I'm a Balisong person, kinda present around here but not really...anyhow that should at the least tell you what sort of stuff we'll probably end up discussing in this thread, if it takes off and goes anyplace that is.

My first question I have not been able to decipher on my own is how people achieve the beatiful even grinds on the blade that give its initial shape that becomes an edge once sharpened. I think I understand that flat grinds would be done on a belt grinder or maybe a table grinder or something, but the hollow grinds I've seen tend towards such a hollow that even using the radius of a grinding wheel doesn't seem like it would give as deep a hollow as I think I'm seeing...

Anybody care to explain and maybe take some pics opf the process if you have anything you could show?

SKIVIE · Jul 5, 2005

Yes, Hollow grinds are done on the radius of the wheel. As far as the consistancy of the grinds your seeing......lotsa practice. Good luck !

Shane

butcher_block · Jul 5, 2005

the belt is on a wheel when grinding, the out side of the wheel that is
there are many different size wheels so the hollow part can be sized right for the knife use
i have no pictures, i do flat grinding sorry and i olny know a little about other styles for now
thats going to change after i get a real nice grinder like a kmg

Robert Dark · Jul 5, 2005

There is no real "magic" in hollow grinding. Folks have been doing it long before 2X72 belt grinders were invented. (Ye-old-hand/foot-powered-round-grinding-stones)

When I started learning to grind, I started with the hollow-grind on a 10 inch wheel. This sized wheel works well for me on knives that are around 1 1/4" to 1 1/2" in width. (flat grinds scared me.....they still are harder for me to do right)

Even though makers use different techniques (eg. "free-hand", use of a "tool-rest", or even using some type of grinding "jig", it all boils down to.......practice, practice, practice. Sorta like learning to drive a car.........very few ever got it right on the first try.

I'm sure that "somewhere" on these forums, someone has some photos. If I had some, I would gladly share.

Robert

fitzo · Jul 5, 2005

The wheels available for hollow grinding on knifemakers' grinders go all the way down to 1/2" diameter. One can get as dramatic a hollow as one could imagine. They also go up to about 14" for a hollow that approaches a flat in appearance.

Good luck with your project. Enjoy.

Gawker · Jul 5, 2005

Well, I kinda think a dramatic hollow would look good on this project due to the artistic concept...this thing is not intended as a working knife, more as a display piece...although the damned thing had better be a good quality knife or it just wouldn't be worth the effort. Course I imagine I'll probably carry it as a gentleman's dress blade pretty rehularly, which is yet another reason I want it to be a well done knife.

I think if I had the access to the few tools I THINK I'd need I could pull it all off, luckily my design is for a tanto bladed knife to there shouldn't be much difficulty in pulling off matching grinds in either side of the blade using the tool rest or something to control the grind...anybody located in or around the Midland/Odessa TX area with a mill and grinder I could borrow?

ANGRYMOB · Jul 5, 2005

You are in for an interesting journey, friend....sounds to me this is gonna cost alot more than having a knife made

J.Wade · Jul 6, 2005

Here is a pic of my grinder set up for hollow grinding.

and one of me doing a hollow grind

you should probly get a bit better resperator thou.(normally I always wear one when grinding.)

as far as a tanto not being that difficult..... well... you'll see

hope this helps

jimi

ANGRYMOB · Jul 6, 2005

[

as far as a tanto not being that difficult..... well... you'll see

hope this helps

jimi[/QUOTE]

Yeah, I was going to say something about that, too. The first few I tried, key word being tried, were tanto grinds.....hopefully you will have better luck than I...I am not even going to think about a tanto for the next year...

Gawker · Jul 6, 2005

well ok...so maybe I'm overestimateing my abilities a bit...what if I were to blank the blade and then ask someone to grind it FOR me? think some of you fellows would be willing to do that little bit of nastiness to save me the embarrassment? I'm going to be doing the blade in damascus anyhow so I'd probably have to end up sending the blade itself off for hardening and etching anyhow so why not have the grind done at the same time right?

Think it'd be too hard to find someone to do all that for a good price? Hell...the thing with this is that I DO want the knife made a certain way and I'm afraid if I just give a basic outline of what the knife should look like a custom maker would get a knife done that I wouldn't be happy with unless I was able to be involved all along the way in order the get the knife I want.

Maybe I oughta just get in touch with someone and get a price for this and have the thing done, it's just that honestly...I've seen a lot of customs that would be totally worth their price but I've seen just as many, that while pretty, just don't look like they're worth what is being asked for them...

ANGRYMOB · Jul 6, 2005

Gawker said:
well ok...so maybe I'm overestimateing my abilities a bit...what if I were to blank the blade and then ask someone to grind it FOR me? think some of you fellows would be willing to do that little bit of nastiness to save me the embarrassment? I'm going to be doing the blade in damascus anyhow so I'd probably have to end up sending the blade itself off for hardening and etching anyhow so why not have the grind done at the same time right?

Think it'd be too hard to find someone to do all that for a good price? Hell...the thing with this is that I DO want the knife made a certain way and I'm afraid if I just give a basic outline of what the knife should look like a custom maker would get a knife done that I wouldn't be happy with unless I was able to be involved all along the way in order the get the knife I want.

Maybe I oughta just get in touch with someone and get a price for this and have the thing done, it's just that honestly...I've seen a lot of customs that would be totally worth their price but I've seen just as many, that while pretty, just don't look like they're worth what is being asked for them...

I wasn't trying to knock you, it's just that that is exactly the thought process I had in the beginning, so it made me chuckle to myself a bit remembering how pissed I was to discover that what seemed the easist was so freakin hard. Those little flat grinds do seem like they would be easier, but to me, they are really hard. Good luck, but remember, once you start, it's hard to stop.