• JR Knifemaker
    76
    So which carbon steel do we prefer for making chef’s knives?
    I’ve only used 1095 thus far, but from what I’ve read doesn’t take too well to bring ground too finely before putting the edge on.
    Thanks all
    Jake
  • Jeff Kushen
    47
    From what I have experienced and seen, many use 1095, 1080, 80CRv2 and 52100. I have only made about 10 chef's knives and those were all 1095. I never had any issues with not having a very sharp, very fine edge..in fact thats the reason its so often used.

    I think Its all in the heat treat...if your grain structure is too large, you may have over heated it and that can make the edge brittle. If you tempered it much over 450 you may get more flex in the blade, but you trade off on edge holding.

    Just my thoughts...ymmv.
  • JR Knifemaker
    76
    Thanks Jeff. I like those thoughts! I was thinking 1095 myself. Grateful for confirmation that it’s not madness!
  • Jeff Kushen
    47
    The forum has been eerily quiet lately...I hope some others like Geoff or Mareko chime in, they use a LOT of HC for kitchen knives...
  • WingOnWing
    0
    I just got a bunch of 80crv2 in from NJSB that I'm going to be using for some chef knives for my family. Got a good tip from several knifemakers at Blade Show West for heat treating: it needs a fast quench oil to get properly hardened. McMaster-Carr 11 second quench oil was the one recommended to me.
  • Smith Knifeworks
    50



    1095 is a good knife steel. It's a spring steel, technically. That's how industry categorizes it, anyhow. It's a hypereutectoid steel, so, from my understanding, it has enough (an excess) carbon to form Cementite (iron carbides) which can aid in wear resistance.

    Really, overall, it's a "perfectly good and fine" knife steel. It's not gonna hold an edge like some of the tool steels and powdered voodoo steels, but it gets GNARLY sharp if the HT is good. You should expect that attribute from any simple carbon steel from 1060 to white 1 and beyond. It should sharpen easily and take a very keen edge, which makes it sort of ideal for making a cutting implement that doesn't require thousands of "cycles" or cuts without needing sharpening.

    I've ground 1095 as thin as you could quantify "thin" before it just becomes a zero grind to sharp. I grind it to about .004" at the edge before sharpening on 1/8" stock that's a touch over 2" tall at the heel. This yields a full flat grind that is very thin behind the edge.



    I would caution people to avoid 1095 from certain suppliers. I found some I had to be non-homogenous steel after beating my head against heat treatment for nearly a month. More on that in private, if anyone desires.



    Good, clean 1095 is about as close to Hitachi White 2 as you're gonna find outside of Europe and Asia.


    It has low manganese content, so it will form a Hamon. This also influences hardenability, It's shallow hardening and requires a fast ( seriously. it has to be super quick. Less than 1 second to get below the curve on the graph.) quench. Industry specifies water, but this is typically in sections over 1/4" thickness. Parks 50 is what you want for 1095 in knife thicknesses. any other oil is a waste of time IMO. Get it from the oil pace in Texas or Kelly Cupples. Water if you're brave, but anticipate a failure rate that's very high unless you really get down your process with clay coating the blades, quenching in warmed water/brine etc. See Murray Carter HT'ing white steel for an idea of how to quench 1095 in water. Consider that he is quenching San Mai and not "Honyaki" knives. You WILL have a high rate of failure quenching monosteel 1095 knives in water.

    I ramp the oven to 1475-1500 and soak for 30 mins. Insert the cold blade and soak for ~10 mins. Remove and quench in parks 50-straighten as needed. I quench and then place it between a surface plate an an anvil with a very flat face before it falls to the martensite formation temp. This makes the structure "set" while it's being mechanically forced "straight and true" and this seems to work with no adverse impacts. Cool to the touch and temper in a VERIFIED 400 degree f environment. This should yield 62-63 HRC if you achieved full hardness (66ish) out of the quench.


    Grind it after temper. Dunk often. Grind it very thin. It will make a screaming laser of a knife.

    Raise a burr at 300 grit and strop on a loaded leather strop for a crazy edge thats somewhere between a saw and a razor. It's hell on food, but has to be touched up often.


    Take it to 6K grit and strop it for a razor.


    It's great steel.
  • JR Knifemaker
    76
    this is a fantastic response! Thanks mate.

    I have a load of 80crv2 as well. Come recommended?

    I’m more worried about Craig’s laptop going bang and no episode this week!!
  • JR Knifemaker
    76
    yup! 100th episode too I think.
  • WingOnWing
    0
    This will be my first time working with it, so I have no idea yet! Tomorrow my goal is to forge out two blades with it, so we'll see how that goes.
  • Smith Knifeworks
    50
    I should note that 1075, 1080, 1084 and 1095 will give you, essentially, the same result as far as performance is concerned. This is, of course, assuming that the heat treat on all samples is of equal attention to detail and correctness, they're at the same hardness etc. Normalizing is important, too. Especially if you don't know what state the steel you have is in.


    I will say that my experiments with 1075 would only yield a max hardness of 59hrc post temper. I was tempering at ~250F and 59 hrc was the hardness it drew back to- verified on several samples. I'm suspecting that the "1075" I had was more like 1060. It definitely wasn't getting to low-mid 60s out of the quench. I suspected more like 61 or so. That's another rabbit hole to go down. The steel you have is very likely not *exactly* what you think it is. For example- 1095 may be anything from 0.9%-1.0% carbon. I think 1075 can vary from 0.65%-0.8% carbon. That's a wide range of tolerance.

    I guess the real subject worth discussing, in that particular situation, if placing 1095 against other plain carbon steels, is-- "Can you tell the difference between steel at 59 hrc and 62hrc?" Some people probably can. Most people probably can't. Kitchen knives are about the only application where you'd even want a knife that was well into the 60s RE hardness.


    15n20 ( another steel from industry. It's just 1075 with nickel added for toughness- developed for saw blade applications) has proven, for me, to make a great kitchen knife. One of my favorite knives I made was 15n20 on its own. I drew it back at 400 degrees, so it was likely mid-high 50s HRC ( I never tested it.) and it performed great. The edge came back on a strop over and over and over. I ground that one very thin pre-sharpening and it never gave me any trouble. no edge chipping, breaking, rolling or other bad behavior.
  • JR Knifemaker
    76
    thanks mate. Very helpful stuff. I’m quite confident on the heat treat since purchase of paragon kiln. I dial in the exact recipe and hope for the best. My knowledge on metallurgy is lacking. So I trust the manufacturer’s guidelines. So far so good. You’ll always be ball park at the very least a if you follow their rules.
    1095 has been my favourite steel even before kiln days. I could get a good performing knife from my ghetto heat treat set up! “Heat it up, cool it down!”
  • Smith Knifeworks
    50
    I typically go by Kevin Cashen's data if I want to develop a base heat treat procedure. I trust his heat treat info without question.

    For what it's worth- I found my evenheat to be 15-30 degrees off. I discovered it while trying to sort a good heat treat on (steel I didn't realize was) junk steel.

    If you're inclined to verify- Table salt melts at 801/1474 degrees. I used that bit of info to determine chamber temp of my oven. I was 20 degrees low inside the chamber on average.
  • eeny
    5
    Some exceptionally helpful info in this thread guys, thanks for sharing! :clap: :up:
  • JR Knifemaker
    76
    that’s a huge tip! Will table salt give off any sort of vapours or fumes that will affect the inside of the kiln?
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