H1 Fixed blades

[yablanowitz]

The serrations are ground all at once on a shaped wheel. It isn't the heat that causes the work hardening, it is the mechanical/abrasive removal of material that does it. That's why it is always hollow ground, since that process is done on both sides at once. Grinding one side at a time results in blades warping among other problems when the second side is ground.

H1/H2 is special stuff, and it doesn't really act like conventional steel. I'd be willing to bet Spyderco ruined more than a few blades learning to work it.

[Stuart Ackerman]

You can file H1 with a chainsaw file...but be prepared to take about 15 minutes for EACH large serrated concave profile.

[JoviAl]

The serrations are ground all at once on a shaped wheel. It isn't the heat that causes the work hardening, it is the mechanical/abrasive removal of material that does it. That's why it is always hollow ground, since that process is done on both sides at once. Grinding one side at a time results in blades warping among other problems when the second side is ground.

H1/H2 is special stuff, and it doesn't really act like conventional steel. I'd be willing to bet Spyderco ruined more than a few blades learning to work it.

Top info, thanks Yab

I’ll have to rethink my approach somewhat.

[JoviAl]

You can file H1 with a chainsaw file...but be prepared to take about 15 minutes for EACH large serrated concave profile.

I’ve got plenty of those kicking about. I might try and hog out the initial stock removal with a conical carbide burr, then switch to a hand file for the last bit. It’ll either work or be an expensive lesson, but as is often the case the painful lessons are the most poignant.

[JoviAl]

I’ll be gunning for a similar shallow scallop profile to my much loved/abused Caribbean.

[sal]

Hey Al,

What is it you are trying to achieve?

sal

[JoviAl]

Hey Al,

What is it you are trying to achieve?

sal

I can’t find an SE Aqua Salt for sale anywhere but I’ve secured a PE one on the secondary market from a guy in Japan. I’m planning on turning it into an SE using my chainsaw porting tools and a bit of patience (or possibly a lot of patience ).

[JoviAl]

I was hoping to find an SE and a PE, but I’ve searched high and low and they’re like trying to find rocking horse . To be honest, I quite enjoy this kind of challenge.

[Doc Dan]

I don't think it works that way. I think the work hardening is in the manufacturing, at least I remember it being that way. Sharpening doesn't do it...though I have read some that say it will after a long time. I think it is a case that the teeth get a little rounded and therefore cut better. Those little teeth act like so many small knives and they really cut.

I’m familiar with work hardening from working with steel during welding applications (where you have to take measures not to over harden and crack your surrounding area from repeated grinding, hammering, bending and heating cycles), but I admit I’m unsure as to how grinding teeth into H1/2 might work harden it from factory. I can only speculate what the exact process of grinding teeth at the factory looks like (or if they are laser/hydro/sonic cut), but I’m going to have a stab at spooling my Foredom up to about 30,000 rpm and getting some serious heat built up at the grinding area, letting the new proto-serration cool, and then repeating until I have the full serration scallop cut (then doing the next one). That might be enough to stress the atomic structure and allow it to plastically deform into a work hardened state.

I find it amusingly ironic that I’m going to try and do something which I normally have to take such pains to avoid

I don’t wreck the knife.

Wow! Well, I hope that works. If it does, you will have discovered something that will help all of us and will answer a great mystery.

[JoviAl]

I don't think it works that way. I think the work hardening is in the manufacturing, at least I remember it being that way. Sharpening doesn't do it...though I have read some that say it will after a long time. I think it is a case that the teeth get a little rounded and therefore cut better. Those little teeth act like so many small knives and they really cut.

I’m familiar with work hardening from working with steel during welding applications (where you have to take measures not to over harden and crack your surrounding area from repeated grinding, hammering, bending and heating cycles), but I admit I’m unsure as to how grinding teeth into H1/2 might work harden it from factory. I can only speculate what the exact process of grinding teeth at the factory looks like (or if they are laser/hydro/sonic cut), but I’m going to have a stab at spooling my Foredom up to about 30,000 rpm and getting some serious heat built up at the grinding area, letting the new proto-serration cool, and then repeating until I have the full serration scallop cut (then doing the next one). That might be enough to stress the atomic structure and allow it to plastically deform into a work hardened state.

I find it amusingly ironic that I’m going to try and do something which I normally have to take such pains to avoid

I don’t wreck the knife.

Wow! Well, I hope that works. If it does, you will have discovered something that will help all of us and will answer a great mystery.

Thanks Dan We Brits love a glorious failure almost as much as a roaring success (some might say more), so it’s a win-win whatever the outcome.

[Stuart Ackerman]

Al
I would suggest using a black marker pen to blacken the area that you want to cut.

Start with a tri-angle file to get the position, and file to almost the desired depth you think you need.

THEN use the chainsaw file to get the profile.

[JoviAl]

Al
I would suggest using a black marker pen to blacken the area that you want to cut.

Start with a tri-angle file to get the position, and file to almost the desired depth you think you need.

THEN use the chainsaw file to get the profile.

That sounds sensible. It’s the TiCN coated version of Aqua Salt I’ve got coming, so it might make seeing the pen marks a bit tricky. I have plenty of layout fluid and a scribe though if needs be. Thanks for the tip

What size chainsaw file do you normally opt for to get a nice scallop? If I’m going the hand filing route rather than using my engine porting gear I’d guess a 9/64 for the narrow scallops and a 7/32 for the wider ones?

[Stuart Ackerman]

The Ti coating will act as a guide, so no worries.

Use whatever you want to use...this is a "see what happens" trial?

[JoviAl]

The Ti coating will act as a guide, so no worries.

Use whatever you want to use...this is a "see what happens" trial?

Very much

[JoviAl]

Worst comes to the worst it’ll just get reprofiled with extreme prejudice.

[JoviAl]

So…the knife arrived and is a thing of functional beauty. Then my wife claimed it as her own having just completed her Forest School operator certification. I couldn’t say no - she really loves it

Back to the drawing board

[SaltyCaribbeanDfly]

So…the knife arrived and is a thing of functional beauty. Then my wife claimed it as her own having just completed her Forest School operator certification. I couldn’t say no - she really loves it

Back to the drawing board

Smart move Al

[JoviAl]

So…the knife arrived and is a thing of functional beauty. Then my wife claimed it as her own having just completed her Forest School operator certification. I couldn’t say no - she really loves it

Back to the drawing board

Smart move Al

I try to be gracious in defeat

[Doc Dan]

Well, she has good taste in knives and a smart husband.

[JoviAl]

Well, she has good taste in knives and a smart husband.

thanks Dan, although the latter assertion is debatable - I managed to stick myself with it real good whilst giving it a sharpen for her. On the upside, as least it’s had its requisite drink now and hopefully will leave my wife alone.