Post Production Heat Treat?

BePrepared

BePrepared

Joined
Aug 26, 2010
Messages
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If a person were to receive a custom knife, and find out that it was only hardened to Rc 56 or so, would it be possible to have it re-heat treated to increase that up to 59-60?
 
You could re-treat the blade if you needed to, but of course if you did that you'd have to take apart/remake everything else and re-polish the steel after. It might be easier from the maker's perspective to just make a new knife.
 
Add to that the good possibly of the blade warping slightly and it would be a quite risky proposition.
 
i'll level with you folks... i'm considering buying a knife from a guy about whom i know virtually nothing. I have seen 2 people say good things about his knives after receiving them, but nothing resembling a torture test or even comprehensive review.

His knives LOOK awesome, but i'm worried that i'm going to get it in my hands it it won't be properly heat treated. I really have no REASON to think that it won't, but call me paranoid

He's asking under $100 for the Kukri that i'm looking at, so the price makes me less worried...
 
If you are buying a Kukri, why would you want it hardened more than 56/58? It is designed for chopping, not for slicing. If you hardend a long blade designed to hack into wood and the possible occasional nail, rock, etc, then you don't want a hardness of 60 because the edge will chip rather than roll.
Jason
 
let me stop laughing long enough to put this in perspective

You are buying a "custom" Kukri for $100

You have not mentioned what steel it is made out of

you do not know what the hardness is

you are already asking about rehardening it

First of all, "Custom" means made to order per your specs, if you did not specify how it is to be made or modified, it is not "custom"

Most Kukris sold in the US are made in India or Pakistan from soft scrap steel and can be carved with the average factory made jacknife

If you don't know what the steel is that it is made out of how do you expect to heat treat it properly?

If you really want this particular knife, buy it, use it, and if it doesn't live up to your expectations consider it a lesson in shopping expectations, if it does what you want it to you got a bargain

-Page
 
I'm kinda with Page there. But here's a story for you.

I finished a knife out of D2 once, brought it to a fellow maker for HT since I have no oven, and sent it to the customer. Months later, he says he bent the tip, got curious and had it RC tested by a friend. Curious turned to furious when he found it was in the high 40's. He sent it back to me, I froze the knife, popped the scales, liners and mosaic pins off the tapered tang,and sent the blade to Paul Bos. It came back unwarped, barely tarnished, and Rc tested to 60. I put the knife back together with the same scales, pins, and liners, shined it back up, and sent it back to the customer.

That's the most serious warranty issue I've ever had by far, and I was able to disassemble and re-HT it with success, but it was a pain in the neck and from it I learned to NEVER trust another maker to HT for you without testing WELL afterwards.
 
The steel is 6150 (yes 6150 not 5160)

it's only custom in that it's not a production blade, and i've asked for minor changes in the handle shape and scale material... The seller has no rep that i'm familiar with although a few guys on THF have bought his blades and say good things

I'm not expecting much... just wondering if i have options if it turns out that the blade is softer than i'd like
 
If you are talking about the blades that "nipsip" is selling at knifedogs, then you might want to ask him about his heat treat methods. So far he hasn't been able/willing to answer too many questions other than price and availability.
Jason
 
He has already admitted that he's selling knives made by someone else. He doesn't seem to be a knifemaker himself, although he makes the sheaths

I asked him about the HT yesterday, but haven't heard back yet.

He has said he'll refund my money 100% if i'm not satisfied, and he does have 2 people i know of that have received his knives and are happy with them..

i'm just the paranoid type
 
I know that some will say spend your $100 and buy it. I'd say to stay away if you aren't 100%. If you want a cheap kuhkri then get one from cold steel and rehandle it or get one from HI.

Just my .02
Jason
 
I already have one from CS :P

I am pretty sure that he's legit, but i really don't have a clue about the quality of his product.

Aesthetically they're beautiful, with nice grinds, good fit and finish, and nice sheaths, and if the final product is properly heat treated, it will be easily worth more than i'm spending.

If it's not, i'll send it back or file a Paypal dispute. I'm not overly concerned about losing my money.
 
An approximate answer is that it is oil quenched at somewhere between a bright red and orange/red color (1500F-1600F) which leads to a RC hardness of 52-54 range. I cannot be more exact than that.
Click to expand...

that's his reply to my email... RC of 54 isn't going to yield a usable tool is it?
 
52-54, AFAIK, will work, but will be sub-optimal. His HT does not seem very precise, which also might lead to problems. I would be talking out my butt, but I would be very cynical.
 
according to what he's told me, HE doesn't make the knives, so he's just guessing. He says he'll contact the person who makes them and get me a precise answer tonight


we shall see
 
BePrepared, I don't think you're being paranoid at all; you are asking very reasonable questions and if you don't get a quick, precise answer... look elsewhere.

"If it sounds too good to be true... " ... you know the rest :p
 
The color he is mentioning is about right but the actual color SHOULD be bright orange like a cooked carrot- note this is a specific temperature. Being general " orange to red" is not. Decent material quenched in water at the bright cooked orange carrot color will bring a consistent temp and Rockwell. RC55 is just fine for a rough use chopping tool like an axe or a Kuke....I would say...try this person's stuff and see what you think. It is not too expensive and he does have a few people that really like them. Either way, post your results and so on on here for us to see.

The amazing thing about metal in general is all you have to do is add heat and old metal becomes new again...
 
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"cooked carrot = specific temperature" my behind! How'd ya cook it? What species of carrot was it? This sort of thing is utter baloney sausage, and a disservice to any craft that seeks excellent, repeatable results.

I'm sorry to go off on a tangent, but I spent nearly 15 years in the printing industry, where colors can be measured by actual wavelength, and have never seen two pressmen agree on any color, by eye, to any measurable degree. Certainly not by whether or not a smith was standing in the full- or partial-shade and may or may not be colorblind to one degree or another.
 
james terrio said:
"cooked carrot = specific temperature" my behind! How'd ya cook it? What species of carrot was it? This sort of thing is utter baloney sausage, and a disservice to any craft that seeks excellent, repeatable results.

I'm sorry to go off on a tangent, but I spent nearly 15 years in the printing industry, where colors can be measured by actual wavelength, and have never seen two pressmen agree on any color, by eye, to any measurable degree. Certainly not by whether or not a smith was standing in the full- or partial-shade and may or may not be colorblind to one degree or another.
Click to expand...

Right on!
26 years and 2 RIT degrees in commercial photography (a good portion of my business was high end (Cibachrome) color printing for Cornell students and faculty) and a Masters in printing (also from RIT) I'm a bit of a color geek. James is absolutely correct about perceived color used as a temperature control unless they have a spectroradiometer to measure the blackbody radiation (infrared thermometers are not applicable in the visible ranges) eyeballing the temperature is subject to variations in perception on the order of almost 200 degrees range depending on ambient illuminant and latency issues. Unless they are judging their temperature based on observed decoalescence and recoalescence thresholds (which will give Austentitic phase change but not carbide former solvus) then they are basically talking out their posterior

-Page
P.S. I once got in an argument with a clothing vendor about whether the "Black" leather I ordered was "Black" or "Brown" and mailed the garment back with 17 pages of colorimetric analysis comparing it to 3 accepted standards of "black" leather and "brown" as measured spectrophotometrically under Standard Illuminants A, B, and C in Munsell, and L*A*B* values :D
 
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