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View Full Version : steel and heat treatment questions (specifically about k110 aka D-2)



SHOKR
08-20-2011, 09:17 AM
I have few questions about heat treatment
I know almost nothing about it really and here (in Egypt) I found K110 steel, the equivalent of D2 I believe, the heat treatment guy says:
1 Iíll have to buy the steel Ďthickerí than what I originally need and remove the outer (deformed)layer, is that correct? Because I found if I buy thickness of 10mm and width of 60mm Iíll end up with like 7.6mm by 54mm
2 after heat treatment the blade (or any steel in the form of a bar for that matter) will be bent or curved a bit, and the to minimize that I have to either have 2 holes at the tips of the steel for heat treatment for hanging (which is not practical for knife making of course) or only heat treat the edge with small part of the handle. is that how its done? Or the entire blade?

I know that most of the grinding is done before HT and the rest is done after, why is that?

The whole process is kind of a blur so really any info would help me understand, things arenít that easy here, I even looked a lot for carbon steel and found only one that supplies steel twice the thickness I would ever need :S

another question about the steel
which of these 3 would be better for starting knowing i'll be using stock removal method and will be sending the blades to be heat treated

https://lh4.googleusercontent.com/-ZiKGeS2O0bw/Tk_RFEV8NJI/AAAAAAAAAy8/tz4c9ElPHj8/s800/d2.JPG



many thanks

Ausbrooks
08-21-2011, 10:21 PM
Maganinooo, I am no expert but will tell you what I know to help answer your questions:
Steel thickness is reduced when you grind the 'bark' off it, which is usually only .005 to .010 inches. After you do a couple you'll get a feel for blade thicknesses. You can also buy "ground" bar stock, which is pre-ground and ready to go, but is a little more expensive. Check out the steel at Midwest Knifemakers Supply at top of this page.
Heat treating- use the holes in handle to hang blade for quenching or heat treating- no need to drill extra holes.
Edge hardening can be done by heating steel and dunking edge into a pan of quench oil with clay on spine. Search threads on this site as there is a lot of data on these methods around and books and videos available.
As far as steel bending during HT and quench- if you are heating in a forge, you need to stand blades on spines and then plate quench w. aluminum plate which keeps blades from warping. If you are quenching in oil, you need to dunk vertically in oil and move only edge wise in oil. I have done both and have not had a blade warp.
Grinding is done before HT because it is much easier to grind softer steel and will save you belts and time and not overheat.
D2 and D3 steel are good knife steels. Never used D3 but looks like a good steel as it has 11-12% chrome which makes is corrosion resistant and has slightly higher C (carbides) which makes it slightly more wear resistant than D2. Most newer makers use an oil hardening steel to start out as it is inexpensive and hardens with a torch and oil quench. Alloy tool steel such as D2 require precise temperature control to harden properly so you need a forge with a pyrometer to do right and also it responds well to cryogenic treatment which requires a dewar for liquid nitrogen. You just need to read everything you can get your hands on for a while on HT and it will start to sink in. Also post more questions on the "new to knifemaking" forum as there is a wealth of expertise in all areas of knifemaking here and your questions will be answered. Hope this helps- there is a lot to know in knifemaking so don't complicate your process to start out with and concentrate on refining your basic craftsmanship and the rest will come.

SHOKR
08-22-2011, 12:32 AM
thanks a lot Ausbrooks!

i will be sending the blades to be 'professionally' heat treated, i think they know all about it, i just wanted to make sure of few points, because knife making entirely isnt given much attention here, save for few blacksmith who would make knives for butchers or few machetes!

i am not really trying to complicate things, except here i couldn't find carbon steel to begin with, only found D2 and D3, so wanted to look further ahead into the process to decide to use them or not specially since finances are abundant (here steel is sold by the kilogram, 1kg of carbon steel would cost $1.4, while D2 would cost close to $7.7)

but i guess costs will be higher in the trial period at first! i'll try to read more on the process

thanks again

Knifemaker.ca
08-22-2011, 07:58 PM
I'm really curious about the K105 and K110 "hardening temperature" of 650 to 700. IF that is not a typo, this is weird stuff. I'm presuming these temperatures are Celsius, and that is about 300C lower than I would have guessed for an alloy like that. With D2, we a short stress relief soak at near that temperature and then harded after a good long soak at about 1010C.

SHOKR
08-24-2011, 12:00 AM
I'm really curious about the K105 and K110 "hardening temperature" of 650 to 700. IF that is not a typo, this is weird stuff. I'm presuming these temperatures are Celsius, and that is about 300C lower than I would have guessed for an alloy like that. With D2, we a short stress relief soak at near that temperature and then harded after a good long soak at about 1010C.

i got that off a website when i was searching the equivalents of the steel, it has nothing to do with my local HT, but i'm not really sure about the correctness of the temps

SHOKR
08-24-2011, 12:14 AM
these are the data from the manufacturer

http://www.bohler-uddeholm.co.za/english/files/K110DE.pdf

http://www.bohler-uddeholm.co.za/english/files/K100DE.pdf

Knifemaker.ca
08-24-2011, 07:15 AM
these are the data from the manufacturer

..... (http://www.bohler-uddeholm.co.za/english/files/K110DE.pdf)

Now that sounds more like it. Thanks!