Differential hardening

[CallsThunder]

I have a question about why the blades are hardened mostly in the chopping area but less near the tip and near the handle. I understand the idea of hardening the edge and leaving the spine softer to absorb impact and reduce the chance of a blade being brittle and breaking. I have read on this forum more than once about edges (usually near the tip) bending over. It would seem that it would be better to harden the edge throughout the length. The spine could still be softer and fold-overs would be reduced.

I do have one theory that I would like confirmed or refuted. Is the softer tip better at cutting softer materials such as vines, grasses etc. It would make sense then to have different hardness levels on the edge...one area for chopping hard wood and the tip or near handle for fine carving or cutting softer materials.

I have learned so much from the discussions on this forum and really appreciate all of the time and effort you all put forth in support of this superb blade. Thanks.

DanR

 

[munk]

Once you start chopping, you'll see it's only a matter of time before the forward thrusting tip finds trouble for itself while the sweet spot is busy chomping wood. I've had the tip strike the ground many times, and rocks live on the ground. The tip is left soft because a hard tip might snap off- how would you like to have that flying around as you delimbed a tree?

The design is pretty well thought out. Some of the Kamis extend the hardened edge farther than others, but the concept is the same.

I'm not a knife guy- I'm not quite sure why the edge is softer towards the handle. The are above the bolster is under a lot of stress. It does not see heavy chopping, and it may be it is left more resilient to absorb the impact energy. A very hard edge in the narrow of the blade, which is what we're talking about, might not allow the khuk to last as long.


munk

 

[Berkley]

it's only a matter of time before the forward thrusting tip finds trouble for itself while the sweet spot is busy chomping wood. I've had the tip strike the ground many times, and rocks live on the ground. The tip is left soft because a hard tip might snap off

:

 

[TomFetter]

Not sure on why the kamis leave the edge softer near the handle ... but it works out for me in practice. I find the softer edge is easier to bring back quickly to dangerously sharp ... and that's the part of the edge I'm likely to be using doing drawknifing type tasks. Takes just a lick or two to freshen up the edge, as with the relatively soft steel in good kitchen knives.

 

[CallsThunder]

Thanks guys. I appreciate the input. It makes sense to prevent the tip from breaking. Bending is much better than breaking I suppose.
DanR