It doesn't always work

Proof that I don't always get it right ...

This was a blade that I started ... did the basic shaping and hardened it, but then decided I did not like the look so I put it aside for another day.  A couple of weeks ago I decided to use it.

First I heated it in the forge and allowed it to cool slowly in an attempt to remove the hardness.  Then I re-shaped it to something I was happier with.  I re-hardened it (I know that part worked) and then tempered it to remove the brittleness, or so I thought.  Today I started to clean it up with Emery paper.  Looked like it was going fine until I saw a crack in the steel.  No way to recover from that!  😡

I was not sure at what point the crack had been induced.  I was able to snap the blade in two in my bare hands with very little effort.  I put one part in the vice and gave it a moderate tap with a hammer.  It snapped in half with no resistance.  So clearly the blade was still very brittle, proving that the tempering process had not worked.  In the second photo the blackened area shows where the crack had formed.

On the positive side, at least it happened now before I finished all the polishing and the assembly of the handle.  Now I know that I need to learn something more about tempering hardened steel.

Knife 08

I took inspiration for my latest knife from the Japanese Tanto, meaning "short sword".  The style traditionally had a blade length between 150 and 300 mm, often with a slight curve and always with a firm scabbard (sheath).  Originally used by the Samurai as a stabbing weapon for close contact defense, the Tanto later evolved to become more ornate as other swords gradually gained popularity on the battlefield.  Eventually the Tanto found favour among women due to it's small size and was often worn as an accompaniment to ceremonial dress.

I chose to make a small Tanto out of an old file that was worn and damaged, which I repurposed for the blade. I first had to remove the hardness by heating it in the forge and allowing it to cool slowly, after which it was easier to cut and shape before re-hardening.  I kept the blade shape very simple because this knife is all about the external appearance.

The handle and scabbard are cut from a single piece of English Oak.  The handle was simple enough with a hidden tang, but for the scabbard I first had to cut it on the centre line down its length.  Then I used my router to cut a blade-shaped recess in each half, just a little over half the thickness of the blade.  Next step was to line the inside of both recesses with soft leather to prevent scratches on the blade.  When I glued the two halves back together there was a leather-lined slot just big enough to fit the blade snugly.

The guard is made of 6mm brass (0.23") with a thin aluminium spacer behind it, matching the aluminium cover surrounding the blade slot.  At the end of the scabbard and the handle there is a thin decorative plate of brass.  After assembling, shaping and polishing all the parts I applied lemon oil polish to the Oak to protect it and enhance the natural appearance of the wood with a rich shine.

Dimensions are

Overall size : 227mm x 24mm x 18mm (8.9" x 0.9" x 0.7")

Blade : 117mm x 15mm x 3mm (4.6" x 0.6" x 0.1")

Handle : 99mm (3.9")

Enjoy the photos!