Page 1 of 2 12 LastLast
Results 1 to 20 of 21

Thread: Spyderco Military S90V Hardness.

  1. #1
    Spyderco Forum Registered User Bluegem's Avatar
    Join Date
    Jan 2009
    Posts
    7

    Spyderco Military S90V Hardness.

    Hello.
    Can somebody tell me what the hardness of Military S90V blade is?

  2. #2
    Spyderco Forum Registered User El Tigre's Avatar
    Join Date
    Mar 2008
    Location
    Argentina
    Posts
    338
    I think, 59-62 rokwell

    "El Tigre"
    Folding knives can be classified in two large groups: Spydercos and the rest!

    Please be patient, I dont speak english properly.

  3. #3
    Spyderco Forum Registered User Bluegem's Avatar
    Join Date
    Jan 2009
    Posts
    7
    Well, that's a large range of values. S90V hardened to 58, usually lose about 10% of S90V performance, hardened to 60, on manila rope. I bought S90V variation, but haven't gotten it yet. So it is not possible for me to test it, and I could not find any information over the net, about Spyderco's s90v heat treatment.

  4. #4
    Spyderco Forum Registered User bh49's Avatar
    Join Date
    Feb 2006
    Location
    former Constitution state
    Posts
    8,327
    Quote Originally Posted by Bluegem View Post
    Well, that's a large range of values.
    I do not consider this a large range for few reasons:
    1. Military is production knife and blades heat-treated in large batches, so there is variation in hardness between blades in the same batch, also variation between batches.
    2. The knife has 4" blade, so I will not be shocked, if there is about one point variation in the same blade.
    3. To the best of my knowledge, accuracy of the most (probably even all) hardness testers +/-1 point. That means that the same Rockwell test block(a master used to calibrate a hardness tester) can be measured 59 HRC on one tester and 61 HRC on second tester.

    Quote Originally Posted by Bluegem View Post
    S90V hardened to 58, usually lose about 10% of S90V performance, hardened to 60, on manila rope.
    It can be true, but I would love to see a source of this information.
    Quote Originally Posted by Bluegem View Post
    I could not find any information over the net, about Spyderco's s90v heat treatment.
    It can be one of two reasons. Either Spyderco using heat-treat process recommended by manufacturer of the steel, otherwise it is proprietary information.
    "People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf"
    George Orwell
    Any knife without Spyderhole is defective.
    My top choices Native5, G10/VG10 Caly 3.5/3 & C83 Persian Black micarta/bolsters

  5. #5
    Spyderco Forum Registered User Bluegem's Avatar
    Join Date
    Jan 2009
    Posts
    7
    Quote Originally Posted by bh49 View Post
    I do not consider this a large range for few reasons:
    1. Military is production knife and blades heat-treated in large batches, so there is variation in hardness between blades in the same batch, also variation between batches.
    2. The knife has 4" blade, so I will not be shocked, if there is about one point variation in the same blade.
    3. To the best of my knowledge, accuracy of the most (probably even all) hardness testers +/-1 point. That means that the same Rockwell test block(a master used to calibrate a hardness tester) can be measured 59 HRC on one tester and 61 HRC on second tester.
    H-mm.
    1.It is usual for knife makers to write hardness of the blade in specs, and it is normal to be +1 -1 HRC, but not +3 -3 HRC. Military is production knife, but that changes nothing for me, Paul Bos works with production knives too, and still he has small hardness range and great final result.
    3. http://ts.nist.gov/MeasurementServic...26,%202005.pdf
    Quote Originally Posted by bh49 View Post
    It can be true, but I would love to see a source of this information.
    That's my own experience, to trust it or not is up to you. And of course, you can always ask Phil Wilson( http://www.seamountknifeworks.com/AboutPhil.htm ), AFAIK he had same opinion.

  6. #6
    Spyderco Forum Registered User cobrajoe's Avatar
    Join Date
    Jun 2006
    Location
    Nebraska
    Posts
    2,434
    Quote Originally Posted by Bluegem View Post
    H-mm.
    1.It is usual for knife makers to write hardness of the blade in specs, and it is normal to be +1 -1 HRC, but not +3 -3 HRC. Military is production knife, but that changes nothing for me, Paul Bos works with production knives too, and still he has small hardness range and great final result.
    3. http://ts.nist.gov/MeasurementServic...26,%202005.pdf

    That's my own experience, to trust it or not is up to you. And of course, you can always ask Phil Wilson( http://www.seamountknifeworks.com/AboutPhil.htm ), AFAIK he had same opinion.
    The variance between 59 and 62 is 3, or +1.5,-1.5.

    +3,-3 would be a total variance of 6.
    MEMBER OF THE INTERNATIONAL ORDER OF THE SPYDEREDGE

  7. #7
    Spyderco Forum Registered User bh49's Avatar
    Join Date
    Feb 2006
    Location
    former Constitution state
    Posts
    8,327
    Quote Originally Posted by Bluegem View Post
    H-mm.
    1.It is usual for knife makers to write hardness of the blade in specs, and it is normal to be +1 -1 HRC, but not +3 -3 HRC. Military is production knife, but that changes nothing for me, Paul Bos works with production knives too, and still he has small hardness range and great final result.
    I believe you, that custom maker like Phil Wilson can heat-treat S90V to 59/61 (per his web site), but I if 59/61 HRC is the spec for custom knife, than 59/62 is not that bad for production. Also, if custom maker will find hardness of the blade 60 HRC, using his calibrated tester, somebody else can find hardness of the same blade the same or two points different, using different calibrated tester.
    Also production knife made a lot of difference for all of us in the terms of the price.

    Not sure, why did you bring certificate for SRM2811. Per ASTM E18, section C, SRM2811, along with 2810 and 2812 are used to calibrate test blocks.
    The test blocks come with calibration certificate, where 5-7 reading recorded, and stats are calculated. Test blocks engraved with average +/-1.
    If hardness tester found within this spec, than it can be used. Hopefully you forgive me that I didn't go through calibration procedure in greater details.
    Most likely it will be boring for most of members of this Forum
    "People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf"
    George Orwell
    Any knife without Spyderhole is defective.
    My top choices Native5, G10/VG10 Caly 3.5/3 & C83 Persian Black micarta/bolsters

  8. #8
    Spyderco Forum Registered User jimbo@stn24's Avatar
    Join Date
    Oct 2004
    Location
    Alberta Rockies
    Posts
    455
    I would guess with Sals penchant for cutting performance the Rc would be such that the steel could perform very well and would be surprised if any blade tested below 60 Rc. My barely educated guesstimate would be 61 to 62 Rc for S90V.

    On the subject of testing, if one had access to 20 different makes of Rockwell testing equipment, if the Rc of the blade was expected to be 60 Rc from the heat treat protocol, I would put money on at least half of the test equipment would provide results that fall between 59.5 and 60.5 Rc. I can't imagine you would see very many values below/above 59/61.

    I wonder if this is an area where the sigma testing values come into play?

    Just read your post Roman, thanks, kinda interesting to me at least. Makes me want to delve into the subject a little deeper.
    Last edited by jimbo@stn24; 01-26-2009 at 12:56 PM. Reason: new information came to light
    WTC #1455

  9. #9
    Spyderco Forum Registered User Bluegem's Avatar
    Join Date
    Jan 2009
    Posts
    7
    Sorry. I haven't slept last night, so my thoughts are a little bit messy.

    Quote Originally Posted by cobrajoe View Post
    The variance between 59 and 62 is 3, or +1.5,-1.5.

    +3,-3 would be a total variance of 6.
    Ok, Ok, I forgot to write zero slash and "or".
    0/+1 or 0/-1 and 0/+3 or 0/-3.
    That's Better.

    Quote Originally Posted by bh49 View Post
    I believe you, that custom maker like Phil Wilson can heat-treat S90V to 59/61 (per his web site), but I if 59/61 HRC is the spec for custom knife, than 59/62 is not that bad for production. Also, if custom maker will find hardness of the blade 60 HRC, using his calibrated tester, somebody else can find hardness of the same blade the same or two points different, using different calibrated tester.
    Also production knife made a lot of difference for all of us in the terms of the price.
    59/62 is still weird for production knives. Benchmade for example http://www.benchmade.com/products/pr...aspx?model=740 , Blade Hardness: 58-60HRC. And as for Phil Wilson, he can heat treat S90V blade from 56 to 61 HRC, according to his measurements, heat treatment will be different for various purposes. Fillet knife will be softer, hunter and utility knife will be harder. But that doesn't mean that he uses this range for all his knives. Here is a quote from his article about S90V heat treatment(http://www.seamountknifeworks.com/Up...0v%20steel.htm).
    Note: As written above when I first started using 420V (S90V) I was limited to about 2000 F by the furnace itself and by the stainless foil used to protect the steel from de-carbonization. I later built a high temperature furnace and found out about high temperature foil. I can now go to 2150 on a routine basis. The results are much improved, the finished hardness now for all my 90V blades is 60 to 61 Rockwell. The cutting and edge holding at the higher hardness is vastly improved over what is reported here. The toughness is still adequate for a working knife. (2006) Phil
    Quote Originally Posted by bh49 View Post
    Not sure, why did you bring certificate for SRM2811. Per ASTM E18, section C, SRM2811, along with 2810 and 2812 are used to calibrate test blocks.
    The test blocks come with calibration certificate, where 5-7 reading recorded, and stats are calculated. Test blocks engraved with average +/-1.
    If hardness tester found within this spec, than it can be used.
    Sorry, wrong URL. The point was that it is possible to use several testers, calibrated with different test blocks, and than just find arithmetic mean.
    Quote Originally Posted by bh49 View Post
    Hopefully you forgive me that I didn't go through calibration procedure in greater details.
    It's a pity, that would be really interesting for me to listen.
    Do you have Military S90v, if yes; it would be great, if you could measure the hardness of the blade.
    Last edited by Bluegem; 01-26-2009 at 04:34 PM. Reason: Misprint found.

  10. #10
    Spyderco Forum Registered User cobrajoe's Avatar
    Join Date
    Jun 2006
    Location
    Nebraska
    Posts
    2,434
    Quote Originally Posted by Bluegem View Post
    Sorry. I haven't slept last night, so my thoughts are a little bit messy.


    Ok, Ok, I forgot to write zero slash and "or".
    0/+1 or 0/-1 and 0/+3 or 0/-3.
    That's Better.

    ...
    S'alright I was just trying to point out that +/- 1.5 is actually quite close to the +/- 1 HRC that the test blocks have. I mean, that is if spyderco factors in the uncertainty of the tester/calibration blocks into their advertised hardness rating (If they did, then if you test a blade on any calibration and tester, it should still fall within the values they give no matter the variance in the hardness or the variance in the tester).
    MEMBER OF THE INTERNATIONAL ORDER OF THE SPYDEREDGE

  11. #11
    Spyderco Forum Registered User bh49's Avatar
    Join Date
    Feb 2006
    Location
    former Constitution state
    Posts
    8,327
    Sorry, I do not have S90V Milly.
    "People sleep peaceably in their beds at night only because rough men stand ready to do violence on their behalf"
    George Orwell
    Any knife without Spyderhole is defective.
    My top choices Native5, G10/VG10 Caly 3.5/3 & C83 Persian Black micarta/bolsters

  12. #12
    Senior Member
    Join Date
    Dec 2006
    Location
    BC Canada
    Posts
    985
    Quote Originally Posted by Bluegem View Post
    Well, that's a large range of values. S90V hardened to 58, usually lose about 10% of S90V performance, hardened to 60, on manila rope. I bought S90V variation, but haven't gotten it yet. So it is not possible for me to test it, and I could not find any information over the net, about Spyderco's s90v heat treatment.
    Here ya go, right from the factory.

    Thermal Treatments
    Annealing: 1650F (900C), hold 2 hours, slow cool no faster than 25F (15C) per hour to 1000F (540C), then furnace cool or cool in still air to room temperature.

    Annealed Hardness: Approx. BHN 277.

    Stress Relieving:
    Annealed Parts: Heat to 1100-1300F (595-705C), hold 2 hours, then furnace cool or cool in still air.

    Hardened Parts: Heat to 25-50F (15-30C) below original tempering temperature, hold 2 hours, then furnace cool or cool in still air.

    Hardening:
    Austenitize: 2100-2150F (1150-1175C) Hold time at temperature: 10-30 minutes

    Quench: Salt quench, interrupted oil quench, positive pressure gas quench or air cool at a minimum cooling rate of 150F/min (80C)/min) to below 1000C (540C) followed by still air or moderately forced air cooling to below 125F (50C). For optimum vacuum heat treatment response, a minimum 4 bar gas quench is recommended.

    Temper: For an optimum combination of hardness, wear resistance and corrosion resistance, double temper at 400-750F (200-400C). Hold for a minimum of 2 hours each temper. For optimum stress relieving and dimensional stability, S90V may be double tempered at 1000-1025F (540-550C), but tempering above 800F (425C) may result in some loss of corrosion resistance. A freezing treatment may be employed between the first and second tempers, if desired. Freezing treatments should always be followed by at least one temper.
    PLEASE NOTE: Tempering between about 800 and 1000F (425 and 540C) is not recommended. All martensitic stainless steels suffer from embrittlement when tempered in this range.

    Aim Hardness: HRC 56-59

  13. #13
    Spyderco Forum Registered User Bluegem's Avatar
    Join Date
    Jan 2009
    Posts
    7
    Percival, thanks, but I had already seen this data sheet.

  14. #14
    Senior Member
    Join Date
    Dec 2006
    Location
    BC Canada
    Posts
    985
    Quote Originally Posted by Bluegem View Post
    Percival, thanks, but I had already seen this data sheet.
    Oops.

    Well, I guess you could try 'sweet talk'n' Sal, but I think he plays his cards pretty close to the vest.

  15. #15
    Spyderco Forum Registered User The Deacon's Avatar
    Join Date
    Sep 2004
    Location
    Upstate SC, USA
    Posts
    21,264
    Does pay to keep in mind that unless Sal or someone else from Spyderco chimes in and gives the correct hardness or range, or someone posts a link to another thread were he mentioned it, everything in this thread is pure speculation.
    Paul
    My Personal Website ---- Beginners Guide to Spyderco Collecting ---- Kiwimania ---- Spydiewiki
    Dead horses beaten, sacred cows tipped, chimeras hunted when time permits.
    WTC # 1458 - 1504 - 1508 - Never Forget, Never Forgive!

  16. #16
    Spyderco Forum Registered User The Deacon's Avatar
    Join Date
    Sep 2004
    Location
    Upstate SC, USA
    Posts
    21,264
    For those interested in the actual answer, someone who is not a member of this forum but reads it was kind enough to send me a link to this thread on the BladeForums Spyderco Forum where Sal answers the question.

    For those who aren't registered over there....

    Quote Originally Posted by Sal Glesser on BladeForums
    Rc59-60

    sal
    Paul
    My Personal Website ---- Beginners Guide to Spyderco Collecting ---- Kiwimania ---- Spydiewiki
    Dead horses beaten, sacred cows tipped, chimeras hunted when time permits.
    WTC # 1458 - 1504 - 1508 - Never Forget, Never Forgive!

  17. #17
    Spyderco Forum Registered User Morales's Avatar
    Join Date
    Jun 2008
    Location
    Germany
    Posts
    48
    Thank you so much Paul, I've been searching BF for a long time yesterday, cause I knew Sal had posted the answer some time ago, but I just couldn't find it.
    It is useless for sheep to pass resolutions for vegetarianism, as long as the wolves remain of a different opinion. William Ralph Inge

  18. #18
    Spyderco Forum Registered User
    Join Date
    Nov 2008
    Location
    Utah
    Posts
    935
    I have a hardness tester in the back of my office/lab area at work, I'll test the new Mule and my Military next week when I have both in hand. I'll report back at that time.

    That being said, I've check at least half of my knives and all of the Spyderco's tested have been within the stated range according to the old data sheets. Sal and company aren't fibbing on the hardness numbers. It's just part of that Integrity they talk about.

  19. #19
    Spyderco Forum Registered User
    Join Date
    Nov 2008
    Location
    Utah
    Posts
    935
    Ok, so I finally took the time to test my new Mule and my Military 2nd that I have on hand. All these are averages of 3 tests. The calibration just before was an average of 56.1 on a 56.4 HRC test block. Since that's within tolerances, the numbers below are straight reporting, no adjustment in numbers due to the calibration error.

    Mule - 59.2 HRC
    Military - 58.8 HRC

    Keep in mind some of the earlier comments about accuracy of calibration blocks and of the test itself and you'll see that this is right where it needs to be.
    Last edited by JLS; 02-12-2009 at 02:11 AM.
    42 Spyderco fixed blades and counting...

  20. #20
    Spyderco Forum Registered User jimbo@stn24's Avatar
    Join Date
    Oct 2004
    Location
    Alberta Rockies
    Posts
    455
    Thanks for the info and taking the time to test and report JLS. Gotta go back and read the data sheet from Crucible now.
    WTC #1455

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •