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Quench plates, the man the myth the legend

Discussion in 'Shop Talk - BladeSmith Questions and Answers' started by JTknives, Aug 4, 2019.

  1. daizee

    daizee KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 30, 2009
    Thanks for that live data point, JT. It's not the answer I wanted to hear, but it was the one I expected. :(
    Not a fan of hard-grinding or hard-hand-finishing. It's probably my finishing practices that have to change first...
  2. seanj

    seanj Gold Member Gold Member

    Mar 1, 2010
    I've had good success tapering a tang in AEB-L after heat treat. So far it's the only stainless I've used. I've found it relatively easy to grind after heat treat.
    Scaniaman likes this.
  3. butcher_block


    Dec 6, 2004
    my Al plates have been good to me but for mass HT loads they do get hot but i still remember that the key is 2000f under 1000f in a min or so. even hot plates make that work. all this said i have often thought about different options. one combo that might be a great set up is 2 inch steel plates with 1/4 inch copper faces and thermal paste between copper and steel. the thought is copper pulls the heat out the blade annd then the steel allows it to transfer and soak in/out of the main surface
  4. seanj

    seanj Gold Member Gold Member

    Mar 1, 2010
    That's a really good idea. That's exactly the way a heat sink works on a computer processor. I doubt you would even need 1/4 inch copper. Copper plate would probably be sufficient.
  5. Metalhead0483

    Metalhead0483 Basic Member Basic Member

    Jan 17, 2008
    It doesn't really effect me right now (still doing forge heat treating right now, and sending my SS off) but it's definitely an interesting read.
  6. Cushing H.

    Cushing H. Gold Member Gold Member

    Jun 3, 2019
    That IS a good idea. I wonder though if the thermal paste could get so hot it would “boil” ... or sputter or whatever. Would have to try it and see i guess...
  7. JTknives

    JTknives Blade Heat Treating www.jarodtodd.com Knifemaker / Craftsman / Service Provider

    Jun 11, 2006
    I would be carful using copper. There was something I read that said one company was using water cooled copper quench plates and thy where test to be as fast as quench oil. Thy where quenching small washers.

    But why go with copper. Faster is not always better. And like was pointed out you have 2 min to get under 1100°. I had thought about using aluminum plate over steel at one time and and cooling it with radiator fluid. But it’s just not worth the effort. Maybe if you ran a belt furnace and blades where coming out every min. Funny beaus I have been looking at belt and vacuum furnaces lol.
    Last edited: Aug 6, 2019
  8. AVigil

    AVigil Adam Vigil knifemaker working the grind Platinum Member

    Feb 17, 2009
    You can always run coolant through your aluminum plates. I know Jeff Mutz does this and Jay Fisher
    Mecha and Natlek like this.
  9. Nick Dunham

    Nick Dunham

    Feb 15, 2018
    John Grimsmo does water cooled quench plates, but just recirculates from a 5 gallon bucket. It wouldn't be too complicated to build a laminated steel cooling block, if one had a CNC plasma ;). Just enough cooling to keep things in range. That'd save you swapping plates out. Corrosion control would be a consideration for water and steel plates, of course.
  10. JTknives

    JTknives Blade Heat Treating www.jarodtodd.com Knifemaker / Craftsman / Service Provider

    Jun 11, 2006
    ow why do you have to go and put ideas like that in my head. Lol
    But yeah it would be easy to cut out a snaking path in in say 1/4” and then sandwich that between 2 other sheets. Hell you could then tig weld it all together. Punch holes through the cover plates for puddle welding to hold the core togather. Then surface grind everything flat. Hot damn, man now I’m distracted again.
    Mecha, Storm W, drew1972 and 2 others like this.
  11. Storm W

    Storm W KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Feb 19, 2019
    What about using aluminum plates attached to your steel plates. I believe they make conductive past that you could add as well. I have some stainless pots and pans. Some are cheap IKEA that my wife bought that are solid stainless and the others ha e aluminum cores. There is a huge difference in how well the pans heat. Or perhaps you could do a bronze brazed surface and machine it.

    Do you know and guys from Hewes Marine? Back when I worked there we were allowed to buy anything less then a half sheet at scrap price. If I recall there was a fair bit of 1/2 scrap from the transoms on the larger boats that you could cut into strips and bolt or weld together.
    Last edited: Aug 8, 2019
  12. Natlek


    Jun 9, 2015
    Do you notice how the top plate does not lie straight, lies on its side and can not touch steel/knife on all surface ? This is quench plate i will make for multiple knives at once , with adjustable screws for any thickness of steel I quench , so top plate can rest right on steel not on one side /edge...and will have incorporated nozzles in tube for even air cooling , just connect air to tube and ......
    Last edited: Dec 30, 2020
  13. MT Borg

    MT Borg

    Jun 14, 2007
    Ok crazy idea time, was just thinking that 4" steel (aluminum) square tubing that is say 1/4" thick is pretty inexpensive. Needing to lose 1,100 degrees in 2 minutes, maybe this could be a solution?
    Both the circumference and internal area is 16" and has an internal air chamber for rapid air cooling along a large surface area. Possibly the steel would not warp and temperature loss would be rapid... Hummm what do you guys think?
    razor-edge-knives likes this.
  14. Hankins

    Hankins KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 7, 2008
    4 X 4 x 1/4" square tubing sounds like an option Maybe with some solid steel plate welded to the top for weight
  15. Natlek


    Jun 9, 2015
    I never HT stainless for now .I know what i know from here and internet so no practice .One or two weeks ago i worked on this 52100 blank forged from ball bearing / I want to experiment with Bainite / I notice that blank is little bend lengthwise . I didn't want to use hammer because i can make some dent in already ready blank so i heat it to 830 Celsius and press it between this two Aluminium plate / 10mm thick / Blank come straight BUT .............When i try to drill 3mm hole in tang .....no way !! That MF hardened way over 50 Hrc ..... new HSS cobalt drill bit couldn't even mark the steel ? And that is oil hardening steel . So i think that Al tube like that would work for stainless..............and it will cool faster then plate for next knife ?

    Then i mark where i want hole with carbide drill bits ....


    Last edited: Jan 1, 2021
    mknife likes this.
  16. JTknives

    JTknives Blade Heat Treating www.jarodtodd.com Knifemaker / Craftsman / Service Provider

    Jun 11, 2006
    I feel people over complicate plate quenching. The best I have found is to use super glue to attach the plate to the vise with rubber. The rubber allows the plate to float and find the flat surface of each blade. All my plate set ups use rubber and thy have been working for years with zero problems. Even the pneumatic plate press is mounted with rubber and its flawless every time.
    Drew Riley likes this.
  17. Hankins

    Hankins KnifeMaker / Craftsman / Service Provider Knifemaker / Craftsman / Service Provider

    Dec 7, 2008
    JT Could you share a pic of your setup...
  18. Mecha

    Mecha Titanium Bladesmith Knifemaker / Craftsman / Service Provider

    Dec 27, 2013

    You just hit on pretty much everything I was going to say. :D

    Not that it seems to be an issue with these air-hardening steels, but the thermal conductivity of the plate changes how it pulls heat AWAY from the point of contact with the hot blade and into the mass of the plate. An aluminum plate pulls the heat away from the hottest point of contact much more quickly than a metal with less thermal conductivity. The area right next to the hot blade is going to rapidly heat up if the plate can't pull the heat away from that spot. Copper is even way better than aluminum in this regard, and as Stacy said, silver is even better. Titanium, having low rate of thermal conductivity, would make for relatively slow-quenching plates, but of course still plenty fast enough for what's being described.

    This is why titanium is said to feel "warm," because it doesn't suck the heat from the skin very quickly.

    It can also be seen when TIG welding these metals. Titanium puddles instantly under low amperage because the heat of the plasma arc column is unable to flow away from the puddle quickly, while TIG welding copper requires way more amperage, and one may not see a puddle until the entire piece of copper has absorbed a huge amount of heat and may in fact be glowing dull red before it puddles.

    I need to come up with quench plates to harden thin titanium that warps horribly in the quench, and will be using 1/4" copper thermal-pasted to bricks of aluminum, chilled in ice water or with ice water flowing through the aluminum bricks, because the quench must be very fast.

    Apparently diamond has the highest thermal conductivity, so how about some diamond quench plates! :D:eek::confused:
    Last edited: Jan 2, 2021
  19. David Schott

    David Schott

    Sep 27, 2004
    This thread made me very happy! While I do have a small set of quench plates, I also have a HUGE stack of what I assume is mild steel in my shop. A year or two a go a friend who does big construction plasma cut up one of those massive metal sheets they put over workspaces in roads and did it into 6X12 chunks and I have about 200 pounds worth and the new surface grinder! Sounds like a project is coming my way for some kind of dedicated setup.
    Mecha likes this.
  20. JTknives

    JTknives Blade Heat Treating www.jarodtodd.com Knifemaker / Craftsman / Service Provider

    Jun 11, 2006
    2 of my quench plate setups use steel and results are undetectable from aluminum. I do know Thy hold heat longer even though thy are similar weight to my aluminum sets. But if your only doing a blade or two then thy are fine.
    Natlek likes this.

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