Combating Chipping?

[Yvsa]

Steely, my guess is that the area that is chipping out is full hard. If you leave a fully hardened, untempered, blade laying around it will sometimes snap completely in half.

Snipped:

If this is something you all would like to see I will do it. I would need someone to post the pics for me though.

I doubt the kamis use a normalizing step. I think they forge the khukuri and then harden and then finish grind it according to the process I've seen them do on video. And I agree that the blade is just too hard, happens once in a great while.
I had to LOL at a website the other day someone had posted where it said the knives they made were from 5160 and that it couldn't be hardened harder than 60 Rc. It can go considerably harder than 60 Rc. The other more knowledgeable guys can correct me if I'm wrong but I think 5160 can reach as much as 63-65 Rc hardness!!!!

Steve if you upload your photos to a host service like http://imageshack.us/ you will be able to post your own pix.
That's really the best way anyhow as it's not eating up the BFC bandwidth the way I understand things.:thumbup:
Even though being a mod gives me pix posting privileges I still like to use the other way better.
I'm going to try the image shack host myself as the pix from there are of better size and quality than from my Yahoo host.

 

[Bladite]

No, we both meant temper. Tempering is the process of heating to a temperature lower than the hardening temperature. This reduces the hardness, and increases toughness. Annealing is the process of completely softening the blade.

We would be differentially tempering by heating the spine of the blade and watching the colors of the polished steel change to a light straw color, indicating proper hardess.

When the kamis harden the blade by pouring water on the edge (hardening), the residual heat in the spine conducts back to the edge, softening it some (tempering).

Many folks mistakenly use the term tempering to mean the entire heat treating process.

Steve

Andy, it probably is internal stress causing the chipping. Just too hard.

Here's a good overview of heat treating
http://www.dfoggknives.com/hardening.htm

i knew i shoulda known that, wonder what my brain was up to? need to get a regular job again i guess...

a self-chipping knife - sounds haunted in a way. interestesting phenomena and weird to boot. glad jake is being taken care of there.

bladite

 

[Steely_Gunz]

i knew i shoulda known that, wonder what my brain was up to? need to get a regular job again i guess...

a self-chipping knife - sounds haunted in a way. interestesting phenomena and weird to boot. glad jake is being taken care of there.

bladite

Well i did threaten ghost knives in Steve's give-away thread I think Sher did his just right, he just got a little too much water on the edge in that spot. I really like the pattern he poured giving the knife a hard area to cut with and a hard point. Besides the phantom chipping, the knife is great. While not a skinner, I think this design has a little more utility than people might think. Not my first choice, but i would be very glad to have it if it was all I had

Jake