Ask JT! the THK FAQ thread

Discussion in 'Terrio HandMade Knives' started by james terrio, Oct 26, 2013.

  1. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    At most. Maybe thinner. I'll just have to make a couple and see whether or not I like the flex (or lack of it).

    The really fun part about kitchen stuff for me is that you don't have to think too hard about overall blade strength/toughness*. Certainly not like you do with a combat/survival knife that might be used for anything from cleaning a fish to hacking down saplings for shelter to who-knows-what. So I get to experiment and learn more about pure cutting performance and geometry... :thumbup:

    *Edge strength/toughness is still brutally important of course... no one wants a custom kitchen blade that dulls in a single meal or chips out on the cutting board or if you glance across a bone... but in terms of people whacking away at trees, digging holes in hard wood and pounding them through cinder blocks and actually breaking the blade... that's not really an issue.
     
    Last edited: Jul 29, 2014
  2. 1066vik

    1066vik Gold Member Gold Member

    Nov 28, 2009
    SWMBO's favorite paring knife is .053 at the spine according to my really cheap (not just low cost) calipers. :)
     
  3. cbwoods67

    cbwoods67 Platinum Member Platinum Member

    Oct 12, 2010
    I'm listening.:D
     
  4. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    Thin is in, baby. Sometimes I can get my hands on .048" CPM-3V... I have a couple test blades cut out of it... you wanna talk about a slicer... :eek:
     
  5. dynamicmoves

    dynamicmoves

    Jan 6, 2011
    That is amazing right there. Wonder how hard it'd be to get .039.
     
  6. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    .048" is as thin as I know of, and frankly I was surprised to find that. There's really no point rolling it any thinner, from the mill's POV. Regardless, it's not much work at all to grind off a few more thousandths once it gets to the shop... a couple thou comes off just by removing the scale. By the time I knock off the mill scale, have them HT'd and get 'em cleaned up, they come out to about .040" at the spine anyway.

    By the time you bevel and sharpen something that thin, it's almost too flexible for all but the most delicate work.
     
    Last edited: Jul 30, 2014
  7. dynamicmoves

    dynamicmoves

    Jan 6, 2011
    So what's the thinnest you're comfortable making a blade in to sell for outdoors work?
     
  8. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    For a typical bushcrafter 4-5" long I like 1/8" stock. It gives the blade enough stiffness and strength to stand up to fairly hard use and can be easily ground to a very keen bevel.

    Naturally you can go thinner or thicker... it just depends on what tasks the knife is built for, and how hard you plan to bash on it.
     
  9. mountainmist

    mountainmist

    Jun 12, 2013
    Hey James,

    Could you give me some in site on how CPM-3V patinas? My understanding is that it is quite corrosion resistant, but when it rusts, it pits and gets pretty orange. I have no experience though......

    Thanks! :thumbup:
     
  10. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    CPM-3V does not "patina" in the way that "plain" carbon steels do. It will indeed exhibit orange surface rust if neglected long enough. That rust does not go deep into the steel and can be basically scrubbed off with whatever you have handy, but it does leave tiny pits on the surface. It's not pretty, but I have not found that pitting to harm the usefulness of the blade in any way. In my experience, 3V is very much like D2 as regards corrosion-resistance. Which is to say... it's dang near "stainless", but not quite.

    Here is a thread I did a couple years ago, with my personal SideKick in 3V (same one you used at the last Beckerhead Gathering)...

    http://www.bladeforums.com/forums/showthread.php/943134-Fun-with-CPM-3V

    CPM-3V can be etched to reduce its shine, and more importantly to help prevent corrosion simply by getting any residual steel dust and other contaminants off its surface. This is commonly referred to as "passivating". 3V that has been finely-finished and then etched in this manner looks really cool.
     
  11. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    Now let's consider why 3V has such good corrosion-resistance for such a fairly simple steel...

    It's all about the chemistry, baby.

    In that thread above, I said this:

    Turns out, I was wrong about that.

    3V only has about .8% carbon in it... that's enough to help it get good and hard (which includes forming ferric carbides) in HT, but there's not a whole lot of carbon left over to form other carbides.

    3V has nearly 3% vanadium in it... that's where the name comes from. Vanadium in tiny amounts (1/2 % of total volume, or thereabouts) helps keep steel structures "tight" and "fine-grained" during HT... this is very good for toughness.

    In larger amounts (2 or 3% and up) vanadium also forms small carbides very readily with whatever carbon is available. More readily than chrome does. < that's very important.

    It also happens that vanadium carbides are much, much harder than plain steel or chromium carbides. Hence, better edge retention without sacrificing toughness.

    So what happens to that 7 or 8% chrome in 3V? Nearly all of the carbon is tied up with iron and vanadium, so there's just not much carbon left for the chromium to bind with. It kinda just "floats" within the steel matrix and resists corrosion.
     
  12. dynamicmoves

    dynamicmoves

    Jan 6, 2011
    What happened to terrioknives.com?
     
  13. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    I let the website expire... it just wasn't generating much traffic and it was a pain to update. I remain undecided about firing it up again.

    I get more business here, it's quicker/easier to interact with people, and I can leave all the pertinent information up for folks to see. And of course, past and future customers can post their own ideas, reviews and comments freely. BladeForums has been very good to me. :thumbup:
     
  14. dynamicmoves

    dynamicmoves

    Jan 6, 2011
    Got it. There's still a reference in the first post of this thread to the site, in case you wanted to get rid of it.

    How hard is a hidden tang knife to make compared to full tang?
     
    Last edited: May 7, 2015
  15. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    Good catch, thanks!

    The blade and handle aren't really any harder to make, just different. The main thing is that fitting a guard properly on a hidden tang naturally takes a little more work.
     
  16. dynamicmoves

    dynamicmoves

    Jan 6, 2011
    No problem. I removed the hyperlink in my quote as well.
     
  17. Noswad0208

    Noswad0208

    Sep 8, 2014
    Hey JT, have you done/do you do any scout/horizontal carry sheaths? Also, what do you consider your best design for EDC-ing? And while I keep coming up with more questions to bombard you with (;)), any pics of that 3 incher you carry that you mentioned in General?
     
    Last edited: Oct 3, 2015
  18. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    Yes I make scout/horizontal sheaths, every knife I make is perfect for EDC (which Terrio knife you should carry every day just depends on where you want to carry it), and yes, there are pics of my hot little three-incher... coming soon!
     
  19. Noswad0208

    Noswad0208

    Sep 8, 2014
    Thanks for the answers!

    What model of yours is most similar to a BK-14 as far as size goes?
     
  20. james terrio

    james terrio Sharpest Knife in the Light Socket

    Apr 15, 2010
    Y'know, I haven't really nailed down a BK-14/BK-11/Izula type neck knife design down yet. There are some really good ones already available, notably those three... and I haven't improved on them enough to make a "standard" THK necker in that size/weight class. Yet. ;)
     

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