HennieL

My research suggest that the USA and Canada made files were made from 1095 high carbon steel. I have made a few knives and daggers from old Nicholson files (mostly Canadian), and can confirm that they heat-treat beautifully using the 1095 HT figures. Due to the high carbon content it is not a very easy steel to treat properly in a forge, as one need to maintain pretty accurate temperatures and soak times, but using an electric kiln it's a breeze. Spheroidize anneal at 650°C for 2-3 hours, harden at 800°C (soak for 10 minutes at this temperature), quench in brine if blade is thicker than 4mm, else in a very fast oil, and temper twice at 230°C for two hours each. Good luck Hennie

Hi Shaun, Ek sal maar in Engels antwoord <_< I mostly make knives by stock removal, but do forge occasionally when forced to (i.e. if I want to make a knife from 52100) I live in Fichardt Park - send me a PM and I will give you my address and phone number - you're welcome to visit... I am a member of the Bloemfontein knife maker's club, and we have a few hard-core forgers in the club that I can introduce you to, should you be interested. Our next club meeting is in 2 weeks time, and you're welcome to join us for the evening - let me know. Regards, (oom) Hennie

And I would love to hunt in Northern Canada - to hunt and fish in the Yukon Territory is high up on my "to do" list... funny that we're never satisfied with what we've got...

Thanks for the nice words, everyone :D Rich, I will certainly give you an "in use" update in a few months - hunting season here in South Africa opens in May, and I hope to have shot something by June... For the time being, I can report that the combination of a high quality steel, and a slightly incorrect heat treatment resulted in a blade with a Rockwell "C" hardness of between 62 and 63 (tested), so slightly harder than what I wanted, but still not too brittle if not used as a chopper. I have since used the knife to cut numerous pieces of thick leather, and perhaps a dozen 1" x 1" pieces of pine brandering, and the blade is still shaving sharp. I'm currently working on my third knife, which will be a little caper, made with N690 steel, to use for the more delicate cutting around the cape, legs, etc. (the second one being a "utility" hunter made with 12C27 that I recently completed). I hope to have the caper completed before I go hunting this year - will post pics once it's done. Hennie

Hi Everyone, Well, looks like I'm doing it all backwards - first I post two technical posts regarding heat treatment (here and here), and THEN I finally introduce myself... I hail from Bloemfontein, South Africa, and have only very recently started making my first knife. I need a good skinner for our next hunting season, and would like one that will stay sharp longer than the average "shop-bought" commercial knife - hence my decision to make my own. I have zero experience or knowledge with forging, so decided to stick to grinding for this knife (I would love to learn how to forge, but that will have to wait another year or two, until I've built myself a decent forge). I did need to heat treat the blade, though, so invested in a digitally controlled electric knife kiln. The knife was made using only a Tormek wet grinder, and hand tools such as an iron saw, a few files, a pedestal drill (with buffer wheel), and lots of sand paper... I made the handle from Lebombo Ironwood, retrieved from an old railway sleeper that was about 120 years old. The steel is from German origin, and is sold in South Africa as Panzer 36 - it is similar to Bohler N690, and I treated it to a Rockwell C hardness of around 59-60, although I have not confirmed this yet. Anyway, enough of that - here are some photos. Please keep in mind that the knife still needs to be sharpened, and it must also still receive a final sanding and buffing, so you will still see some dirt and light scratches on the photos: Here is the knife, together with a wooden model that I made whilst designing it: This will give you an idea of wood to metal fit - I'm quite pleased with how this turned out Hennie

Steve: apology accepted Matt: I certainly did not take your point on cryo vs cold as critical - you are correct, and I appreciate your advice Thomas: Now that's a thought It's actually a "gut hook", located in an unusual place. With it being on the back of the knife, one does not have to turn the knife around when skinning, and the added levarage of pulling down with one's fist, rather than with one's wrist, should make it a lot safer and easier to use - at least that's the theory... time will tell. Thanks again, Matt. Yes, I did everything by hand, using a Tormek wet grinder. Their knife jig is pretty useless for making curved bevels, so ended up with the knife held by hand to grind the bevels. After trying various other home-made jigs and guides, none of which worked satisfactory, I ended up using a little laser levelling device to shine a line across the wheel to act as a guide, and just tried to keep the knife edge on this line - worked very well. Hennie

Thanks, Matt Regarding the semantics: I do apologise for not getting it right , but at least I can put up the defence that English is not my native language - and although you will be exasperated by the exuberance of my verbosity, I do get it wrong from time to time You're probably correct that there is not much to gain by the relatively low (or should that be high...) temperature of the low-temperature treatment (is that better, Steve ), every bit does help - and as you quite rightly state, I do have a freezer... Steve, I do understand that it's frustrating when some youngster asks for advice, and then just ignores everyone who does not give the advice that he wants to hear. As an "old man" myself (I beat you by about 10 years...), I don't suffer fools lightly, but I also don't put up with people being rude to me. Now, let's look at me "ignoring" the good advice:In my first post, I asked advice on keeping oxygen away from the blade being treated, and on the suitability of using paper to use up the O2 during this process - nothing more, and nothing less. I received some advice in this regard, and to remove the foil before quenching, and I accepted this advice with thanks - so no ignoring of good advice there... except for your "advice" not to use the steel that I'm using because it is apparently too complicated for a beginner. In this thread, I asked for advice on the time needed to "soak" a thin blade vs the time specified by the suppliers for much thicker steel. Again, I received positive advice from most people, and again, I accepted the advice regarding the question that I asked... I still don't understand why you want me to use a different steel from what I have already purchased (and spent a long time on shaping...), just because I'm new to heat treating. As an engineer, I solve difficult problems almost every day, and if I do not have the knowledge, I will do research until I'm satisfied that I can solve the problem. Dealing with something like heat treating, I aim to do exactly the same - with your help and experience guiding me, but with me making the final decisions, based on MY evaluation of the problem or challenge... that's what I do Anyway, enough of this. Matt - just for you: Before heat treatment: ...And after: There are no visible cracks, and only one tiny spot of scaling on the back of the tang, where the foil was not properly wrapped - the rest of the blade is just discoloured. I tested it with a file, and even with hard pressure the file just slid over the blade without "biting" at all. I gave it a 4 hour "low temperature" (is that better, Steve ) treatment, then it's first temper at 125°C for 1.5 hours. After cooling, it went back into the deep freezer for a 12 hour "soak", and I will do a second temper at 150°C for two hours tomorrow evening... then it's back to the bolsters and handle for another week or two (remember, I'm doing this all by hand). Hennie

Hi Everyone, Joined the IFI community recently, looking for information on treating a knife steel. Managed to complete the first blade's hardening this afternoon, and glad to report that all went pretty well Wel,ek wou maar net dag se... Hopefully I will be back with lots of questions... Hennie

Sure, that's your definition of it... but if you want to nitpick, cryo is not even a proper word (perhaps rather use cryogenic...) Again, that's what YOU say... I have rather more faith in what the suppliers' data sheet say... Note that the "sub-zero quenching" on the graph below (which is the term they use, and which is in fact more accurate) only drops a little teeny bit below the "0" line (oh, and that's °C...) Steve, I really don't know why you come across so aggressive - I have certainly not given you any reason to be offended, but you have been making snide remarks from your first post on this thread... hey man, ease up Hennie

OK, report back time This morning, I "stress relieved" the blade at 625°C (within a tolerance of 3°C, thanks to the electric kiln) for an hour, then allowed it to cool down to 150°C inside the kiln (took about 5 hours), and then allowed it to cool further in still air to about 25°C. I then wrapped it in a layer of kitchen paper towel, then wrapped it in stainless foil, and heated it up to 1050°C, kept it at that temperature for 20 minutes, and then quenched in oil heated to 50°C until it had cooled down to around 70-80°C, after which I dunked it into cold running water. I'm ecstatic to report that everything appears to have gone OK, with no visible cracks or warping The knife has since been moved to the wife's freezer (around -27°C) where it is being "cryo-treated". If it survives the cold treatment, I will temper it twice, at around 120°C and 140°C, and then give it a final sanding to remove the darkened "skin" (there is only one very small patch of black "crud" on the back of the tang, the rest has just discoloured). Thanks to everyone for the good advise - I'll be mack with many new questions soon :D Hennie

Well, having done my first "heat treatment" of a mild steel clone of the knife today, I must agree - it certainly will need a lot of work to finish it off after being baked at 1050 °C for 20 minutes The reason for going all the way down to 1200 grit was my fear that a scratch close to the edge could cause cracking. I don't know if this is a valid point, but would rather put in a bit more elbow grease to prevent possible problems. I'm aware of that. What I don't know is how thick/thin can the edge be? Would 0.5mm be sufficient? Yes, I have some stainless foil, and have used it on the mild steel "knife" as well, just to make sure that I can properly remove it from the knife before quenching. On tro "treatments2 of the mild steel clone, I once used a piece of cardboard, and the second time some toilet paper. In my opinion, the toilet paper resulted in less black scale forming on the knife blade. When I do the real blade tomorrow, I will wrap it in toilet paper, and then in the stainless steel foil. Phil, I'm glad that you think that my kiln is "fancy" - it certainly impressed me today... heated up from about 22°C to 1050°C in less than 15 minutes, and then kept the temperature within 3°C for 20 minutes whilst soaking the blade. So, tomorrow is D-day for the Panzer 36 blade (if it does not rain...) Hennie

Yes, stubborn as XXXXXX In reality, my supplier is about 450km away from me, and everything must be sent by post or courier - not good if one is impatient... Hennie mod note: foul language removed due to violation of IFI rules

Thanks, Grant - It did take me a few reads, but I did suspect that is what Matt meant. From the little that I've since read about this subject, the molten salts are electrically conductive, and will speed up corrosion of the heating element - I will rather give it a miss at this point in time. OK, then - if the consensus is to first remove the foil, then that is what I will have to do. I will wrap it so that the blade is covered, but the tang is sticking out - I don't mind removing some scale from the tang, but would prefer to keep the blade as clean as possible. Will be practising on a mild steel clone of the knife a few times before attempting the real one. Hennie

Thanks for all the advice, guys Yes, I know that I'm aiming high for a first heat treatment, but my choice in steel is rather limited to good knife steels, and I enjoy a challenge - what can I say... Although I AM new at knife making and heat treating, I do have many years of DIY experience in both wood and metal work, seeing that I've been tinkering since around 1965 or thereabout (I'm 56 years old, and started quite young ) The knife in question (a little skinner that I'm building to use in our next hunting season) has already been shaped, ground (by hand), finished to 1200 grit, brass bolsters made, and African Lebombo Ironwood scales shaped in the rough, so if the heat treatment goes OK I should have a pretty nice knife in a week's time... I just need to learn as much as possible about that subject as I can before I hang the knife in the kiln. I will have a few practise runs with a mild steel copy of this knife, that I made especially for this purpose (I know it won't harden, but I will still gain a lot of experience playing with it before tackling the real knife). Well, off to bed now... have some steel to heat tomorrow Hennie

That's one of the problems - the supplier won't disclose who the manufacturer is... Here's a link to the data sheet on the suppliers' website: Panzer 36 Hennie

Thanks, Matt The steel I'm using is actually called Panzer 36, but as I said above, it is similar to N690, so I suppose the Bohler data should be pretty relevant. The actual spec sheet for the Panzer 36 steel talks about 1 hour per 30mm thickness - hence my question. I don't feel comfortable with just extrapolating the 60 minutes for 30mm to only 6 minutes for 3mm, and unless someone else advises differently, I will use your recommended 20 minutes. Can you (or someone else...) please elaborate on the plate quench method - it's a new one for me Hennie

Hi everyone, I'm a total beginner with regards to heat treating of steel, and am doing my research before attempting to harden my first blade I'm planning to harden a 3mm blade, which is made from a German steel similar to N690. The spec sheet states that the steel should be treated at 1030 °C to 1080 °C for a period of 1 hour per 30mm of thickness. My question is, do I reduce this time by one tenth, given that my blade is only one tenth the thickness for which the treatment time is given, or is there a minimum treatment time for a steel, regardless of the thickness of the material being treated? I will be doing the heating in a digitally controlled electric kiln, which should keep the temperature pretty close to what is required. Hennie

would you care to elaborate on this please... remember, I'm a complete newbie when it comes to heat treating. Hennie

It's an oil quench steel. According to the data sheet, the hardening should be done at 1030 ³C to 1080 ³C for a period of 1 hour per 30mm of thickness, then double tempered at 100 °C to 200 °C, again for 1 hour per 30mm thickness, with a freezing cycle thrown in for good measure... Could one not oil quench with the foil still wrapped around the blade? seems to me that a thin piece of foil would not be much of an insulation to keep the steel from rapidly cooling, but of course I've never done it before, hence the question Thanks, I appreciate all the input and advice. It's quite frightening to venture into the world of high heat Hennie

Oh, I did start slow... first knife was ground and filed by hand (took one week to do the shaping). Once the bug bit, though, I've gone into overdrive and have since bought a very nice belt grinder and electric kiln... so now I'm probably hooked for life Hennie

Oops... I think that should be 0.02" and 0.03" Not used to working in the archaic imperial system Hennie

Thanks for the info so far The blade is 3mm thick, with the cutting edge ground down to approximately 0.5mm (0.2") thickness. I've been toying with the idea to cut this back a bit to around 0.75mm (0.3") - will this be enough? The steel is a German made steel, sold in South Africa as "Pantzer 36" - I could not find much info on it on the 'Net, but here is the analyses, if that can help: Carbon: 1.00 - 1.10 % Silicon: 1.00% max Manganese: 1.00% max Cobalt: 1.30 - 1.80% Chromium: 16.50 - 18.50% Molybdenum: 1.00 - 1.50% Vanadium: 0.07 - 1.12% Thanks Hennie

Hi All, This is my first post on this Forum. I'm from south Africa, and am an absolute beginner as far as heat treating & forging goes - given that my electric kiln is only to be delivered tomorrow Having read up on the subject of heat treating for some time now, I understand the process and metallurgy involved, to some extent, but will only be gaining first-hand experience over the next few weeks... My current concern, is that my first heat treatment project will be to harden a knife that I have just completed. Now, according to many sources on the 'Net, any steel will be degraded if heated in the presence of oxygen, and I have read that one should wrap the knife in newspaper, and then in foil, before heat treating. The foil is supposed to prevent the stainless steel from discoloring, and the wrapped newspaper is supposed to combust, and in the process remove all the O2 from around the knife within the confines of the foil. Is this true? Is it worth doing, if true. Thanks Hennie