What do you think about letting the tip get blue?

Possum...

Let me reiterate here....it all depends on the knife. Most knives do not have true fighting tips nor are they designed as fighting knives at all.

I don't turn every tip blue...it just depends on the geometry of the tip and what the knife is used for.

A true fighting knife tip (ala Bagwell Bowie type) will not withstand a direct drop onto or prying motion if it were the same hardness as the edge...no matter how good the HT or steel. You are better to have it bend where you can put it back rather than to risk losing it all together.

I heard a story about Bagwell (have not asked him if true or not) about purposely bending a tip at a show and putting it straight again.

I agree with rlinger here that getting it too hot will make it brittle also
 
Newbie here.

Rather than giving the tip extra tempering, why not temper the portion of the spine just behind the tip?
 
Rather than giving the tip extra tempering, why not temper the portion of the spine just behind the tip?
Click to expand...

I think that's an excellent idea for some blade shapes, but it wouldn't work for all of them.
 
Hey Greg.
You said, "Let me reiterate here....it all depends on the knife. Most knives do not have true fighting tips nor are they designed as fighting knives at all.

A true fighting knife tip (ala Bagwell Bowie type) will not withstand a direct drop onto or prying motion if it were the same hardness as the edge...no matter how good the HT or steel. You are better to have it bend where you can put it back rather than to risk losing it all together."

With all due respect, I must disagree. One respected smith has already added that his tips can still bend rather than break even at 62 Rc. I've spoken (well, conversed online) with other smiths who have similar views. However, rather than stand on their reputations, allow me to add some of my own experiences.
My big hunting Bowies do indeed have the same requirements of a large fighter, and the tips are fine enough for thrusting. Here's a few stories taken directly from my coon hunting page to illustrate where I'm coming from.

"The coon started moving again, and I did NOT want him to get away, so I decided to try stabbing him through the three layers of chicken wire. To my surprise, the blade cut right through the wire, the coon, into the concrete bin foundation behind him. It actually took me a second to realize it. When the blade stopped abruptly, I just thought it didn't go through the wire, so I shoved harder and worked the handle, until I heard that grinding sound of the point in concrete. (I could barely see what I was doing cause of all the big weeds in my face and poor light) Though my thrust landed in a vital area, when I withdrew, the coon tried running again. Had my blade been too damaged to repeat the performance? Nope. Right through the wire again, and pinned him squealing in place 'till he succumbed in a few seconds. I know for a fact my fist big knife would have been too damaged to penetrate on that second thrust."

My first big knife that I mentioned above had a soft point. How did I know it would be too damaged to perform? One night after killing a coon in our grinder shed, I checked in the silo.... I got into a whole mess up there, but tried stabbing one coon, and the blade refused to penetrate! Seems the point got damaged and bent when I accidentally struck the concrete floor of the grinder shed earlier. I leaned my weight onto the handle, and it only shoved the coon down into the rotten silage- still refusing to penetrate. So I had to finish him with a draw cut.

That's certainly not the only times I've had a point take some serious abuse.

"So as I'm going thru the door, my hand is already on my Bowie, er, I mean Camp Knife, and the beam of my maglite meets the glowing eyes of this ugly assed possum in the cattle trough. As I got near, I drew the blade and made a big swing, but in my excitement, I didn't compensate for his movement at the last second, and I missed completely. Instead, I took a big slice out of the concrete floor, and mangled the last 3-4 milimeters of my point. I vividly recall the shower of sparks. Later, dad said he saw them too."

Same with folders, in this case my Benchmade Ares:
"Just after getting it, I shot a coon in our woodshed with a load of buckshot. Those damn vermin were crapping on a stack of seasoned walnut lumber we have been saving for making furniture, staining it and greatly reducing its beauty and value. He was still kicking, so I stuck him with the Ares. It went thru him and hit the concrete beneath him. As expected, it made a notch in the concrete, but only broke a tiny fraction of a millimeter off the tip of my blade, which I fixed in about thirty seconds with a diamond stone." Also once dropped a handmade folding fighter tip first onto a ceramic tile floor. It is double ground with a needle point, ATS-43 @ 62 Rc. Did half an inch shatter off the point? No, about 2 milimeters bent to 90 degrees.

These are just a couple examples out of many. I am using a true fighting knife tip that you mentioned, and I'm doing a lot worse than simply dropping them on a floor. They are full hardness (same hardness as the rest of the blade), and they do hold up. For me, the choice does not seem to be as simple as, "hard will break, soft will bend". It's more like "hard will break off half a milimeter of the very tip, soft will dull/squash and bend 1/4 inch ". I still choose hard.
 
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I swiped this graph from Crucible's website. If anyone has such a chart for O-1, please share. As you can see, some steels do not act predictably in regards to hardness vs. toughness. This steel is notably weaker at 53 Rc than it is at 56 Rc. And then the curve goes up again. It has about the same strength at 56 Rc as it does at 51 Rc. Of those two, I'll take the harder one. Thanks.
 
Obviously we all have our own thoughts on design. Personally I have no use for thin whippy tips that are of what many feel is the 'fighting knife design'.
Like the Fairborne Sykes Mete mentioned. I lucked into a book about the development of that knife. There were many discussions about style and thoughts about carry and important folks decisions. Not one time in the book was there any mention of testing the knife. Thus is the history of many 'fighting knives'.

The tip has one job and that is to get the rest of the knife into its work.
A well designed tip in my opinion is sharp as humanly possible to develop. That tip is well supported by the geometry of the material behind it.

I like a tip that looking down on it from the spine looks like a cold chissle. Looking at it from the edge side you see a fine piercing instrument on top of a cleanly designed symphony of cut, chop or slice depending on 'what for'.

Bill Burke was driving a guard on one of his bowies using a hammer and drift block. The blade slid down in the vice and stuck in the steel top of his bench. He had to lever it out of the bench. The tip was still sharp, a little disscolored by the steel it had pierced into. Still that tip was fully capable of opening up a beef or small game.

Design is every bit as important as the nature of the steel. One supports and makes the most out of the qualities of the other. Less here, more there, many decisions all based upon testing of the blend you have created. The bladesmith who tests does not simply copy what some historians consider great knives, he takes the time to see, and understand why and what for.

It is all too easy to accept knives that were made as jewlery for men as fighters. The Huber Bowie was one of the outstanding designs of all bowies, she was well thought out. I recently purchased another great fighter handed down through history by a man who obviously was in absolute command of all that went into his knife. She is unsigned and by todays standards a little on the curde side. Still, if I were going into combat, I would consider her a worthy companioin. If any who would like to see her she will be at Blade Show West with me and you are welcome to meet her.

If you can't make it to Blade Show West she will be in a future article in Blade Magazine, lots of photos and enough to think about for those who are interested.
 
I'll have to agree with Ed and Possum, if 1/4" or more of the blade breaks off, the blade probably was, over heated on the point, to hard overall for the working hardness of the steel, or to thin. In all my droping blades point first onto concreat not one has snapped, some have blunted and some have chiped out edge, and a couple have bent just a little. In almost all cases the damage was easy to fix on a stone, most of the time the damage didn't go beyond the sharpened edge. You realy don't need a supper fine thin skinny needle like point on a knife unless your an assassin or surgen, and that's all the knife would be good for. If your worried about a thicker tip penitrating an opponent, shove harder! :D
 
What'd I say about tempering tool steels between 500 and 700 F. The chart backs it up (in a way).
 
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