Tanto - Aizu Shintogo Project

You can re-do the HT . but I doubt the blade is as soft as you say … unless it wasn't hardened right.
As noted by Richard, a 525°F temper would only drop the blade to around Rc58.

Questions:
Does a file skate a bit on the edge or does it just file away the metal?
Was the clay too thick and too close to the edge?
What temperature was the HT done at?
How long did you soak the blade at targer temp?
 
Stacy E. Apelt - Bladesmith said:
You can re-do the HT . but I doubt the blade is as soft as you say … unless it wasn't hardened right.
As noted by Richard, a 525°F temper would only drop the blade to around Rc58.

Questions:
Does a file skate a bit on the edge or does it just file away the metal?
Was the clay too thick and too close to the edge?
What temperature was the HT done at?
How long did you soak the blade at targer temp?
Click to expand...

Yes, the file skates a bit on the edge.

What I did different this time, I put 3 cots of ATP-641, instead of 2. But that’s pretty thin I think.

I brought the oven at 1475F, inserted the blade and held for 30min. The oven got back to the target temp in 5min. Say it took another 5min for the blade to come to 1475F. So it soaked for at least 20min.

Just for clarification, since there are no parallel surfaces left on the blade, I measured the harness
on the bevels that were left at 80grit.

Maybe the combination of inclined and rough surface gave me such an erroneous reading?

I understand it is not ideal to take the measurement as I did, but I didn’t expect to be off that much.

What do you think I should do at this point?

I could perhaps make a coupon leaving a flat area and also grind a beveled area on it, then HT the same way and measure hardness on both surfaces.

Thanks again,
Constantin
 
Heli00 said:
Yes, the file skates a bit on the edge.

What I did different this time, I put 3 cots of ATP-641, instead of 2. But that’s pretty thin I think.

I brought the oven at 1475F, inserted the blade and held for 30min. The oven got back to the target temp in 5min. Say it took another 5min for the blade to come to 1475F. So it soaked for at least 20min.

Just for clarification, since there are no parallel surfaces left on the blade, I measured the harness
on the bevels that were left at 80grit.

Maybe the combination of inclined and rough surface gave me such an erroneous reading?

I understand it is not ideal to take the measurement as I did, but I didn’t expect to be off that much.

What do you think I should do at this point?

I could perhaps make a coupon leaving a flat area and also grind a beveled area on it, then HT the same way and measure hardness on both surfaces.

Thanks again,
Constantin
Click to expand...

In my experience, measuring hardness on either inclined or rough surfaces will give pretty peculiar results. Not trustworthy at all.
 
I decided to continue with the blade regardless, just so I get accustomed and learn how to complete all the stages of the blade, good practice anyway. I’m grinding it off as we speak.

Another question please, what thickness should the HA/edge be before sharpening on a tanto? How much meat underneath the edge should I leave?

Thanks again,
Constantin
 
On my katana I followed advice from Stacy and did a flat grind down to around 0.02", then convex to nothing. It is one of the easiest grinds for me. I did some final sharpening on a big diamond. Ended up very sharp and no secondary bevel.
 
Richard338 said:
On my katana I followed advice from Stacy and did a flat grind down to around 0.02", then convex to nothing. It is one of the easiest grinds for me. I did some final sharpening on a big diamond. Ended up very sharp and no secondary bevel.
Click to expand...
Great, thanks again!
 
Stromberg Knives said:
Haha, that’s strange though. My O1 even at 65 HRC isn’t hard to hand sand at all. Are you using good paper?
Click to expand...
Yes, I’m using Rynowet, but I don’t really like hand sanding and so I whine about it :)
And in all fairness, I started hand sanding at 150 grit, which probably explains it. I guess, self inflicted.
 
Last edited:
Stacy E. Apelt - Bladesmith Stacy E. Apelt - Bladesmith , i’m working on the handle.

I have a question about the hole in the handle.

Should it be a bit offset towards the end of the handle relative with the hole in the tang? So that when inserting the tapered pin it will pull the blade in, locking it better ?

Also, is the pin inserted from the left or right side? (While pointing the blade forward)

Thanks again,
Constantin
 
Oh, by the way, anybody else in the know how is encouraged to answer, :). Hope I didn’t scare you. All input is appreciated.

I called on Stacy because I know for sure he is experienced in Japanese all things.

Thanks,
Constantin
 
Last edited:
I'm really glad to see that you are following through. I almost bumped this to ask.
I got all fired up about tanto and waki and started several myself. I'll start my own thread when they are further along. 2x hamon, 2x San mai, 1 large waki...

Hopefully you will get good answers about the handle construction. To avoid that issue for my katana I sacrificed the takedown ability to put a Corby bolt and plenty of epoxy. I didn't want to gamble on a wooden peg and some rice glue to hold while I swing it around the yard...
 
Heli00 said:
Stacy E. Apelt - Bladesmith Stacy E. Apelt - Bladesmith , i’m working on the handle.
I have a question about the hole in the handle.
Should it be a bit offset towards the end of the handle relative with the hole in the tang? So that when inserting the tapered pin it will pull the blade in, locking it better ?
Also, is the pin inserted from the left or right side? (While pointing the blade forward)
Thanks again,
Constantin
Click to expand...

If I read your question right, you are correct.
The nakago-ana (tang hole) should show on the front of the tsuka-ana (handle hole) with the rear part of the tang hole about 3/4 the way across the tsuka ana. That will pull the blade back and the handle forward, drawing the fucchi tight against the tsuba/seppa.
 
Great thanks Stacy.

Another question please, how do you drill the tapered hole in the handle?

Thanks again,
Constantin
 
You can drill it with one size bit (eg. 3/16") all the way through, then re-drill one side only 1/16" larger ( eg. 1/4"), You can also make a tapered bit by turning down a 1/4" drill bit. Run it in a cordless drill and holding it against the flat platen. Dip to cool regularly. I like the ana to be a tad less than 1/4" on the large side (ura).

BTW, IIRC, the mekugi enters from the ura side. At least, that's the way I insert them.

Also, buy good quality mekugi. Dowels and chopsticks are not right. Metal won't stay tight. Unless it is a she=lf queen, do it right with quality mekugi made from the outer part of cured bamboo.
 
Ok, thanks again.

One more clarification please.

Ura is the side close to the body/stomach when wearing the sword.

If one is left handed, does that mean that it is reversed from a right handed person?

Is the ura opposite on a katana and a tanto?

Thanks,
Constantin
 
Last edited:
You must log in or register to reply here.
Back
Top