Heat Treating Knives, Blades etc

Greeting fellows smiths!!! Been doing lots of lurking, havnt much time for anything. But I want to make myself a small puukko. My questions is exactly how thin do you grind you bevels before tempering? In my past experience, I tempered a scandi, but the bevel was left at about a dimes thickness. I had a really rough time grinding it down to a useable edge. Will the edge be prone to cracking if I ground it down all the way? Or will it hold up. I will be quenching at Curie temp, in some warm motor oil. Most probably will be using an old file or 5160. Tempering at 175 C. for a durable, tough edge. Cheers mates!! Thanks in advance for any help! Michael

I'm making a roughly 12 inch knife out of 1095 steel and have put a lot of work in it. I'd like to know what your most reliable ways of treating 1095 are and if maybe you have any tips that would prevent warping or cracking. I've already had one successful bowie knife made from 1095, but I'd always like to learn more about heat treating. Thanks a lot. :D

I'm in a blacksmithing apprenticeship and I'm trying to make a knife from a crow bar. My idea is to have a super sturdy knife that has the pry head of a crow bar on the butt of the knife. That would make it good for prying (which knives are usually used for but don't axcel at). Anyway I've tried twice to make one, and both knives have cracked in heat treating. DOes anyone know what type of steel crow bars are made out of (I was using a craftsman) and if so how to heat treat them? We were using a salt water solution, would oil have been better? Any info will help, thanks -Blood Groove

First I do not consider myself a "bladesmith" in any way. I make the odd knife for the kitchen or workshop and that is it so my question is just from curiosity. A few weeks ago there was a link to a video posted that showed a sword made and at the end the maker flexed it and really bent it and it sprung straight back to shape. If the sword had a differential temper to have a springy "body" and a hard edge why doesn't the hard edge break off when the sword is flexed? Once again, this is for interests sake only on my part. Thanx

So I am really confused about the whole tempering thing... for example: what is the difference between running the colors with a torch and oven tempering... what is the process for torch... how do you know how long to leave in oven... should you leave to cool in the oven, or let cool at room temp... who, what, how, when, where, and why? Lol I am really confused by this whole process... so if some1 could explain it to me, or better yet if a smith in my area could show it to me... that would be great.

what is the best way to temper a double edged dagger? Im looking to get a good hard edge maybe about 55-57Rc with a softer core. what would be the best way to accomplish this?

hi just a quick question, i have a large leaf spring knife to quench so i would like to add to my quench oil (it has seen only two small knives) do i have to add the same type of oil ie, 10 w 40 or can i mix in ie, 5 w 30 or even canola oil ??? i have some of each.please help as im now stuck.thank you

I ground a blade today and put it my oven to austenitize 1525 F, 5160 double edge dagger. Electric fire brick oven ,(old wax burn out kiln.) When I opened the door almost immediately the tip cooled to black about a 1/4" back. It was ground pretty thin .030 or less. Anybody have this problem or think of a way to get the blade to quench fast enough. I'm sure I can't grind that thin for one thing. Mark

Folks: I've only quenched about a dozen blades of various steels types before, but one thing is already becoming apparent to me which I haven't seen in written this bluntly before.... please let me know whether you concur or if I'm off base with this thinking: There is a direct relationship between how hard your edge ends up being and how much risk you're willing to take by inadvertantly destroying it. Stated differently, if you go the safest routes during quenching, you typically end up with somewhat less hardness than that steel is capable of attaining. Take the biggest gamble, and any high carbon blade potentially achieves its greatest level of hardness. Th…

Hey Steve I am a Beginer knife maker, I have read the other posts, and I still have an unanswered question. Do you sharpen a blade before quenching? and if you do not could you please explain.

Folks: a couple of questions before I risk inadvertantly destroying another knife. (I'd try to answer these questions on my own through experientation but I don't have a forge in my own house, and have to pay for limited forge time at a local educational smithy.) I have an approx 15 x 3/8" blade hammered out from a RR anchor clip. (One gentleman on this forum suggested it's simple steel in the vicinity of 1060-80). I'm going to attempt to quench this with quenching oil in an aliminum roasting pan (like what you'd use for a turkey). 1. Would there be any problem laying the knife on its side at the bottom, or does the oil need to flow freely on each side? 2. Does …

Bashed a blade out from an old file (by hand, no power hammer!) then onto the grinder, and 8 hours later it looked like this,..... I was pretty pleased at this point, forging good, grinding improving a bit, tripple normalised to control the grain size, . yup, well on its way to being a proper knife, had a bit of a guess it was a 'w' series steel, so clay backed it and into the water...... 3 seconds later it looked like this,...... The moral of the story is probably test H.T. a bit of the steel before you chuck a perfectly serviceable blade into a bucket of water :rolleyes:

I hate the term "normalize"! All other thermal treatments are specific to the steel at hand and the rate of temperature change required, air harden, oil harden, water harden. Or anneal at a cooling rate of 50 degrees per hour etc., etc. How come normalize is "one size fits all"? "Heat to critical, allow to air cool". If I air-harden an air-hardening steel is it still "normalizing"? Does an eighth-inch thick piece cool at the same rate as a 2" thick piece? Even air, oil and water harden only refer to a one inch cross-section. You can get a proper hardening on water-hardening steel in oil if it's only 1/8 inch thick. And a four-inch thick piece of 4140 won't harden wort…

When forging a knife, do you forge, then normalize, then grind, then harden, then temper, or do you forge, then normalize, then harden, then temper, then grind?

So if I'm making a knife (something like a buck knife) out of old lawnmower blades, what should I quench it in? Plain water, salt water, or oil... I'm quite confused. Advice would be apreciated.

Heat treating 1084 in an electric oven, I went to 1475 degrees, quenched in ATF at 150 degrees and checked w/file for hardness. Now to temper it takes the oven an hour to cool to 400-, my temper target. In the sticky it mentions the stress at the martensite state, after quench (could crack blade) Any other dangers waiting an hour to temper. I'm using the oven (PID control) for its accuracy and fear of burning point in forge. I'm taking notes and doing #d samples, but don't want to continue down the wrong road. Thanks Mark

OK so I'm finishing off my first railroad spike knife, and I know that the metal is to soft to hold an edge for long. Any hints on how to temper the edge with a propane torch?

anyone tried the japanese style claying on a seax? i am in the process of starting one and would like to know if a japanese hammon would be a good idea or the traditional heat treat method. thanks. :confused:

Hi Folks: a hopefully simple heat treatment question: Once hardened and essentially unfileable, could a blade be annealed again for any major reshaping (by file)? I read somewhere on this forum that it is recommended to happen no more than once. Am wondering how subjective that is, and what the drawbacks are of annealing more than once. Thanks for any feeback!

do Hi all my name is Stanley and have been lurking here for a while an just getting into forging. I have been doing sttock removal for about 5 years. I just forged out my first spike hawk and quenched in brine but now do I need to temper or is the low carbon stable enough as is,If I need to temper at what temps. Thanks Stan

In the many posts showing new knives for critique, I keep seeing comments like "nice temper line" I don't know if I'm blind or what, but could someone show me what a temper line is and how it is made. Thanks in advance

I teach blacksmithing at the local community college. I brought some automotive coil springs to class to make punches/chisels. Forged to shape, brought up to non-magnetic and quenched in water. We got cracks lengthwise, so I tried an oil quench. Some cracked, some didn't. I tried air hardening, some worked, some didn't. Testing with a file produced a strange result......:confused:......Outside layer of piece was not hardened, center was hard. I am pretty knowlegable, but this one has me stumped? Any opinions will be welcomed. Thanks

Can antone give some info in heat treating toolsteel to keep the blade very hard and the back softer to keep the knife from breaking. Thank much T,O,B

i was wondering if i could anneal or normalize a foot of 2 inch leaf spring in my wood stove if i crank up the heat. i want to cut it with a grinder cutoff saw and its way too hard it took me 1 hour to cut the foot off of the main leaf and thats only 2 inches.im going to build my charcoal forge soon but bc of my stupid design (which i refuse to change bcim stubborn and it took me a long time to come to the decision.. blah blah blah....) anyways i cant pour my refractory cement until i get 3 days of 10 degrees or more and the forge is in my un heated garage, and i got a 3 year old and 3 month old at home so not much time on my hands... but if i could anneal it (evenhalf at…

I am having difficulty in understanding heat-treating. I understand that drawing the steel from the full hardened condition produces less hardness and more toughness. I have been told that I should draw the steel three times in order to assure there are no "hard spots" remaining in the blade. I have also been told that it is not necessary to "re-harden" the steel prior to tempering for the second and third times. It seems to me that once tempered, the steel is no longer at max hardness. If I begin at that point and temper for a second, and possibly a third time, am I not reducing the hardness each time, and thereby arriving at a steel that is too soft to produce a good ed…