• TimLandiniKnives
    0
    Since I don't own an Even-Heat, yet, I've been quenching with my forge. It tends to work as I get a hardened blade, but my question lies with the temper. I've read on USAknifemarker that a proper temper for 1095 is at 500F for 2 hours twice to get around 59-60 HRC. I do this, since I'm still searching for the "answer" for tempering 1095, and it comes out a really sweet blue color and according to my Hardness files, its around 50HRC...i missed the mark.

    I'm just looking to pick the brains of people who know more than I do working with this steel. Anyone have the "answer" for me? I know Geoff mentioned in today's live video on the instagram to go 1500F then oil quench, then 400(?) for 1 hour twice?
  • JR Knifemaker
    78
    By no means an expert here, but I’d say two hours is too much. I’ve had the best result from 1095 at 210 for one hour, once. I’d forgotten to add a Spanish knot to the base of the edge, and when I tried, there was no chance: a sure sign that the steel was hard!
  • MakerMark
    1
    I buy my 1095 from gfs knifemaking supplies and this is what the manufacturer recommends
    mfnnl2aua81nds4l.jpg
  • Smith Knifeworks
    52
    I'm no expert, but I've been using NJSB 1095 exclusively for a couple of months. I would say: remember that not all steel, even of the same name, is created equal. So all I can speak towards is the NJSB 1095. It's good stuff. I'm super pleased. The thing about 1095 is that is has a picky hardening curve. The reason you got 50hrc at 500f is likely because it didn't fully harden to begin with. You need to quench 1095 in something fast. Either water/brine ( plan on having a very low success rate if you're quenching stock that is less than 1/4" thick. They will break. Certainly.) or parks 50 (available from maxim oil in Texas). I use parks 50 with great results. My procedure is as follows.

    Steel in a cold Evenheat oven. Ramp to 1475 and soak for 5 mins. Get it out of the oven and IMMEDIATELY into parks 50. I mean as fast as humanly possible without injuring yourself. If it fully hardens, you're looking at something like 66hrc. Real hard. I temper in my kitchen oven, but I've done some playing to get it right. I've determined that my oven, with a sheet pan blocking the top and bottom heating elements, set at 380f, will yield an average blade temp of right around 400f when the blade is placed between the two sheet pans. By Kevin Cashen's data, this should put me at around 62-63 rockwell. I dont have access to a rockwell tester, but i really believe this is where I'm landing. This shit is HARD out of the temper. A file still wont touch it. It's great. You have to consider than an electric kitchen oven cycles the heating elements to maintain the box temp. radiant heat from those elements can bring a work piece up to 50 degrees higher ( in my experience as checked with a temp gun) than the oven setting. So you need some sort of "chamber" or "heat sink" to sort of even things out.


    Temperature is going to make the steel softer. Duration at temperature is not as significant. Duration at temp will influence stresses in the steel, but it shouldn't really make it any softer. The hardness is what it is at a given temper temp. This is my understanding of it. Your issue, to me, sounds like it didn't fully harden and you tempered a little too high. netting a spring, basically.


    If you're not in the position to get a heat treating oven, I'd suggest switching to 1084 and forge heat treating that. It's much more forgiving regarding temp, requires no soak, and will fully harden in a slightly slower quenchant like canola oil or peanut oil. You can take 1084 up to where a magnet doesn't stick, jam it in a bucket of $5 grocery store canola oil and temper in the kitchen oven with very acceptable results. Don't get too caught up in the steel name. The reality is, a decently heat treated piece of 1075, 1080, 1084 will do anything and everything you could ever ask of a knife. The hype around steel types is mostly just hype. Everything is in the heat treat.

    My heat treat method, on NJSB 1095, has yielded edges that, so far, have lasted several weeks in pro kitchens, on poly boards, that only require a touch up. no real sharpening in that time frame. Simple carbon steels like 1084 and 1095 will do everything they need to do if you can get the HT down.



    If you're curious about heat treat methods and information I fully buy into this concept: I don't care what anyone says about heat treating carbon steel ( regarding knife heat treat, anyhow) unless it's Kevin Cashen or some other MS or similar. Guys like Fuad Accawi etc End of story. I've approached it this way with very good results. You have to consider that a lot of the metals we use originated for use in industry. Industry heat treatment is a different application than we use. Most of the standards there are based on procedure for a 1" round bar. For instance- 1095 is a "shallow hardening" steel. It, in theory, doesn't through harden. The catch there is that all of that data is in reference to a 1" bar of 1095. It most certainly DOES through harden in 1/8" sections quenched in parks 50.

    Was that helpful? Sorry. I hope so. I got wound up..hah
  • Smith Knifeworks
    52
    Oh, if you're trying to judge temper by eye, you need to be looking for a straw-gold-bronze color. Blue is blown. That's way too hot. Blue is spring temper territory.
  • TimLandiniKnives
    0
    All the info is very helpful. I don't quench anything thicker than 1/4" most of the time. I've started the heat treat process after I grind it to shape and relatively flat. I used to grind in the bevels first but I had too many issues with what comes out of the oil.

    Speaking of the oil, I bought a bucket of 11 second oil from McMaster Carr when I first started making knives, and with the thickness, or lack thereof, I haven't really had an issue with using that. I'll play around with a different quenchant with this particular steel since I don't have the ability to get a HT oven yet.
  • Chad Kimmell
    17
    All i read from your post was "I'm no expert... but here is really good advice and insight articulated perfectly" lol seriously thank you, thats great insight
  • Smith Knifeworks
    52


    I've come to glean a bit more knowledge since I posted that. There are some things I posted there that I've found to be less than ideal.

    Don't start in a cold oven. Ramp to heat, let the oven soak for a while (20 mins or so) to ensure everything is equalized. Then insert blade, let come to temp and soak for a few mins.

    I was guessing 62-63 rockwell. I've since testes and found my number to ACTUALLY be 61-62. So I was a bit off on that, but close.


    Verify your oven is accurate. Mine was not. Everything I found states that NaCl melts at 1474deg f. My oven was reading about 20 degrees low, which is pretty normal, I gather. Not a huge deal, but you know...for the sake of being accurate and truthful. There that is.


    I have some comments on NJSB 1095 as well, but I'll reserve those for private discussion.
  • Dave Sizemore
    0
    Tim, I understand what you’re dealing with. I’ve come across a lot of the same info online that I’m sure you have with regard to temperature and hardness. I also came across the same issue you described with color. I’ve been working with 1095 a pretty decent amount lately. All I can say is that despite what you read, 500° F in a kitchen oven seems a little hot. I’ve spoken to a couple knife makers that I keep in touch quite a bit about this exact topic with this exact steel and both of them told me to go 400° F for 2 hrs twice. As mentioned in previous posts, not to beat a dead horse, a lot has to do with if you actually got your steel fully hard and if your oven is calibrated to an accurate temp. If you think you’re at 500 but in fact you’re 550 or more for example, that can obviously be a big issue.
  • WingOnWing
    1
    Have you made sure your oven temps are actually accurate? For sure get a little oven thermometer and double check that your 500F (or whatever you're tempering at) is actually the temp you intended.
  • JH Forgeworks
    5
    Holy Lazarus thread batman

    If he hasn't figured it out in the last 11 months, I don't think it's gonna happen.
  • Jeff Kushen
    49
    Also, as Geoff stated, I would actually put a firebrick ( the hard kind) in the oven and put my knife on that. I put it in when the oven is cold. This will help the blade retain heat more evenly, as commercial ovens are notorious for as much as a 50 degree swing during heat cycles.
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