Forging a katana (WIP) (pic-heavy)

[aurik]

Hello everyone,

I've been dabbling in the blacksmithing/bladesmithing arena for a little over 2 years now.

As I live just north of Denver and my shop of choice is in Colorado Springs, it's generally a one or two weekend per month deal, where I take a full day, drive down to the Springs, and spend the day in front of the forge working on a project. In the meantime, I've also started setting up a workshop in my basement. My wife is adamant about not having a forge in the house, but I've added in a couple bandsaws, a multiprocess welder, a 2x72" grinder, a drill press, and a bunch of hand tools.

I saw that Kilroy's Workshop was offering a katana making class last month, and I jumped at the chance. The class actually filled up in less than a week, even though it was announced 2 months out.

Day 1 of the class involved forging a bar of (W-2) steel into the rough shape of the katana. Getting the tip right was hard -- you have to hammer at a MUCH shallower angle than you think. We started with an oversized bar (1.5") and had to hammer it down to dimension (1.25"). The instructor gave me a few pointers on hammer technique, and that made things go MUCH faster. I was able to get the blade hammered to shape, with a well-formed tang and a very smooth curve without any major issues. I used the power hammer to flatten out the bar, but most of the work was done by hand.

Day 2 consisted of straightening the blade, then profile grinding the blade, grinding off the forge scale, and then establishing the bevels with a draw file.After a couple hours with a draw file, I went ahead and moved over to the belt grinder, but honestly that is REALLY hard to keep consistent bevels on a 30" blade without creating facets. I was able to get pretty close, and then I went ahead and used the draw file to even things out. After that, we thermal cycled the blade, added clay to the spine (to keep the spine soft and to create a hamon line), and then quenched the blades to harden them.

And that's where things went sideways.  Apparently when I applied clay to the blade, I did not put enough clay on the spine. So the spine hardened, the edge hardened, but the sides of the blade did not. As a result of the differential hardening, the blade straightened itself out. To make things even worse, when the blade went through the temper, the tip of the blade bent forward slightly -- enough to be noticeable. Sooooo... day 3 was spent annealing, re-forging the curve into the blade, and re-hardening the blade.

Next step was creating the tsuba.  They 3d printed a tsuba, which I created a sand mold out of.  The trick is apparently to pack the sand enough to keep things firm, but soft enough that the tsuba will still make an impression in.  Once the mold was created, we fired up the kiln, melted some bronze, and poured the bronze into the mold:

The next step was setting up the blade for a tang and a habaki.  I took the blade to the grinder again and made sure the tang was properly profiled and tapered so the widest point of the tang was right where the blade and tang meet.  Then I ground a pair of shallow shoulders into the tang to create a seat for the habaki to sit.  My first attempt at a habaki was a disaster -- I can't solder worth a hill of beans.  The second attempt we just soldered in place, and used some sandpaper to profile it to fit up correctly.  

The next step was to fit up the tsuba.  This required a LOT of work with a drill press (to create the initial holes, a dremel, and hand filing.  It consisted of a sequence of grind/file, test fit to see how far the tsuba slides up the tang, and then look to see where I need to grind some more.  I wanted to make sure I had a good, snug fit (that took a few hours).  Finally, it was time to make the handle.  I had to create a third set of shoulders on the tang to reduce the height of the tang, and then created a coffin-style handle using 3 pieces of 1/4" poplar.  After the handle dried and I got it ground to a comfortable shape, I added a traditional rayskin wrap on either side, and then wrapped using the traditional (synthetic) silk.  The wrapping turned out to be easier than I thought, once the instructor showed me the trick a few times.  The entire handle is held on by a single bamboo pin -- which started life as a chopstick.

Here are the (semi-)finished pics:

What's left?  A LOT of hand sanding to get out the hammer marks and to even out the bevels.  Then even more sanding to bring the edge to an appropriate thickness.  Then yet even more sanding and polishing.  And then sharpening.  At a rate of a couple hours per day, I expect this to take me another few weeks to finish.  But man will it be worth it when I'm done!

Edited August 22, 2023 by aurik

[Zaine]

This is really cool! Thanks for sharing!

[Patrick]

That's awesome! Thanks for sharing.

[sensei8]

You've MAD SKILLS!! Thanks for sharing!!

[Dmitriy]

I like smithing too!