Surprising W-2 various quench medium hardness test results: Brine, Houghto-Quench k,

[Jeff the Millwright]

Anyone who read my thread on testing 1095 with different quench mediums will know that I realized after I normalized my test pieces that the decarb layer was much thicker than I realized so I couldn’t go back and retest the sample pieces to see what the hardness was deeper below the surface.

So I thought I would revisit that test taking hardness readings at various depths on pieces quenched with different quenchants. Because 1095 and W-2 are both shallow hardening hypereutectoid steels with the same heat treat I decided to use W-2 on this test because I had scrap pieces left over from cutting out my knife from bar stock.

Sample pieces punch marked.

Quenchants all at 130F.

I assumed because they were similar steels the hardness tests would be very similar but I was very wrong. The original thickness of the steel was .207” and after heat treating and skimming off the scale the original test thickness was still .207”. I removed accurate amounts of steel and retested at various depths.

No matter how well I line up the columns once I post they don't line up but hopefully it's pretty easy to decipher my readings?


Thickness .207 .205 .200 .195 .190 .180
Amount removed 0 .002 .007 .012 .017 .027

Brine 63 65 65.5 65.5 66
Houghto-Quench® K 48 54 53.5 53 53.5 49
APCO 9-11 second oil: 41.5 42 43 42 42
Canola Oil: 39 39.5 40 41 40

Because my columns don't line up I included a photograph of my notebook showing my readings lining up properly.

The Brine results were about as expected in both hardness and verifying that brine hardens much closer to the surface than other mediums. Also I find the Brine results verification that my methods are sound because these are about the hardnesses expected.

What was very disappointing was my Houghto-Quench® K results. This being a 7 to 9 second oil like Parks 50 I expected my results to be very close to the Brine results. I find this surprising because I did get 65 hardness with 1095 using Houghto-Quench® K once ground down to a depth of about .020” and I thought these two steels were very similar in their hardening requirements.

It did show however that canola seems to be about a 9 to 11 second oil as it performed very close to the industrial oil of that rating which of course are both even more inadequate than Houghto-Quench® K for W-2.

What this test shows me is that W-2 can only be used with a water Brine quench. I was really hoping this test would serve as a double test because I expected the results to be the same as with 1095 but since they aren’t I am going to do the exact same test with 1095 soon.

This just verifies again to me that if you’re going to do your own heat treating you need a heat controlled oven and hardness tester. By the way I placed samples in the oven ramped up to 1475°F and soaked for 10 minutes. All quenching mediums were at 130F.

I did grind off .010” more on my test sample using the Houghto-Quench® K because I was curious if it got harder deeper down because I have 5 gallons of this stuff and some W-2 left over but what surprised me is after I ground down .027” the hardness fell off five points so it is definitely a shallow hardening steel which makes me think it isn’t a great steel for a knife because once you remove that much sharpening your knife you are into soft steel and your knife becomes pretty much useless.

I guess I put the horse in front of the cart because I made a knife using W-2 and quenching with Houghto-Quench® K that I really like but obviously it only has a hardness in the low 50s if I am lucky after tempering. Once again live and learn. So now I’m going to do the same test on 1095 and really nailed down how good Houghto-Quench® K is on it and at what depth. Stay tuned!

 

[P.Brewster]

I would keep going with the tests. I think the factors to look at are (a) volume and/or agitation of quenchant, (b) normalization of the steel, and (c) austenitizing temp.

 

[Cody Hofsommer]

Everyone knows that W2 makes terrible knives! 😬 I'm thinking that you don't have enough volume of oil?

 

[Don Hanson III]

I consistently get 67.5 - 68.5 from W2 quenched in Parks 50.

 

[Willie71]

I had one failed blade returned by a customer a few years back. Bought a hardness tester that day, and test my results on every blade, when possible.

 

[Willie71]

Cross sections under 1/8" should have no trouble through hardening. Wedge shapes also favour hardening in the thinnest section. 1/4" W2 might through harden in oil if you get everything right, but auto hamons are common. The edge should have no problem hardening though.

 

[Jeff the Millwright]

I appreciate the input P. Brewster and Cody Hofsommer and yes I agree that it is possible that the things you mention may have some effect on my final hardnesses but I think they don’t really explain the disparity between the Brine quench and the Houghto-Quench® K results.

As all other factors are equal I don’t think those things can explain why the Brine was close to a perfect quench as far as hardness goes but the Houghto-Quench® K was about 12 points below that considering the only variables were the quench mediums.

I do find these results very perplexing because I did get 65 hardness with 1095 using Houghto-Quench® K once I was convinced to grind down .020” past the decarb layer. This is my 1095 problem all over again but I know the culprit isn’t not grinding down far enough because I did it this time? So I agree with you guys that probably I could increase my hardness a little if I address those issues but that does not explain the 12 hardness point differential between Brine and Houghto-Quench® K with everything else being equal.

And I appreciate Don Hanson III letting me know that you get such amazing hardnesses with W-2 using Park’s 50 because I know you are a real authority in this area and I am kicking myself that I bought Houghto-Quench® K instead of Parks 50 but being Canadian I would’ve had to have it shipped from Texas and I didn’t want to deal with the brokerage fees and hassles. And I kept reading that Houghto-Quench® K and Parks 50 are both 7 to 9 second oils and should perform the same.

I think at this point tomorrow I am going to do the exact same tests with 1095 and if I can get a 65 hardness again after removing a substantial decarb layer like before I will just put the W-2 aside for now.

And Willie71 I do appreciate the info on W-2 and how deep the hardening should be on different thicknesses. Hopefully someone will post something about their hardness tests quenching W-2 with Houghto-Quench® K.

 

[Kentucky]

just curious, did you grind off the mill scale before you hardened the pieces?

 

[Jeff the Millwright]

No Kentucky I didn’t grind off the mill scale but this was awfully clean looking stock but then again I treated all the samples the same and got a hardness of 66 with the brine quench with the mill scale on.

I know we have been through this before with my 1095 and I suspected it was the Houghto-Quench® K when in fact I didn’t grind my decarb layer deep enough so I accept it may be something I don’t understand yet but what has me stuck is that all the samples were treated the same and the only variable was the quenching medium and the fact the Brine sample had such a high hardness makes me think it has got to be the Houghto-Quench® K but then again I have been wrong before obviously, LOL.

Because the culprit on my last test which was not grinding deep enough I addressed that on this test so it is quite perplexing? And why would Houghto-Quench® K harden 1095 to 65 for me and yet treating W-2 which calls for the exact same heat treating I only get a max of 54?

Until someone verifies they get hardnesses of around 65 with W2 using Houghto-Quench® K, I can't help thinking that oil just isn't up to W2. As I said tomorrow I'm going to test 1095 again and be certain it's over 65 and then I'm going to go back to that steel and make some blades while I investigate W-2 further. I'm not selling my knives at this point and I really just want to practice my grinding and finish work and I can worry about perfecting my heat treating with W-2 if I ever decide to sell one. I really like how my last knife turned out and I want to get back to knife making and improving my skills.

 

[Kentucky]

Yea, that's a head scratcher for sure..That Houghton should be hitting 65-66 easy..Maybe try a different aust temp? Not sure it would make a difference but your particular oven may be reading a bit high/low? Its not unheard of... Id try say 1450°-1460° see what that says..go from there..

 

[David Stifle]

No Kentucky I didn’t grind off the mill scale but this was awfully clean looking stock but then again I treated all the samples the same and got a hardness of 66 with the brine quench with the mill scale on.

I know we have been through this before with my 1095 and I suspected it was the Houghto-Quench® K when in fact I didn’t grind my decarb layer deep enough so I accept it may be something I don’t understand yet but what has me stuck is that all the samples were treated the same and the only variable was the quenching medium and the fact the Brine sample had such a high hardness makes me think it has got to be the Houghto-Quench® K but then again I have been wrong before obviously, LOL.

Because the culprit on my last test which was not grinding deep enough I addressed that on this test so it is quite perplexing? And why would Houghto-Quench® K harden 1095 to 65 for me and yet treating W-2 which calls for the exact same heat treating I only get a max of 54?

Until someone verifies they get hardnesses of around 65 with W2 using Houghto-Quench® K, I can't help thinking that oil just isn't up to W2. As I said tomorrow I'm going to test 1095 again and be certain it's over 65 and then I'm going to go back to that steel and make some blades while I investigate W-2 further. I'm not selling my knives at this point and I really just want to practice my grinding and finish work and I can worry about perfecting my heat treating with W-2 if I ever decide to sell one. I really like how my last knife turned out and I want to get back to knife making and improving my skills.

Did you make a mistake somewhere down the line? I suggest you repeat the test once more, as carefully as possible, to see if you can repeat the outcome. If you get yet different results, there's a variable somewhere, the steel quality, heat oven, something...

 

[Jeff the Millwright]

That is actually a good idea David Stifle to repeat the procedure and see if I come up with the same results. I can’t see how there is a variable because I put all four pieces in the oven together and heated up all the quenches together and used the same bar of steel for all the samples. The only variable is that I opened the door four times on the oven to take out the pieces but I did allow the furnace to come back up to temperature and it dropped only about 10°F.

But as I said I’m going to do the exact same test with 1095 tomorrow but I will also throw in another W-2 sample and quench it in Houghto-Quench® K along with the 1095 sample and see what results I get. That was actually a good idea and it will be pretty easy to just do that W-2 sample along with my 1095 tests. And I will make sure to quench the W-2 sample first so the oven is up to temperature. And if I get hardnesses of 65 with 1095 again and only 53 with W2 in the same test it will verify that Houghto-Quench® K is not up to W2.

 

[Jeff the Millwright]

Sorry Kentucky somehow I didn’t see your last post and yes I agree it is a head scratcher? I did suspect my oven may not be reading the right temperature when I was doing my 1095 tests so I did a salt melt test and according to that my oven is less than 10°F out. Besides I can’t see how I could get 66 with brine during the same test if my temps were out?

Tomorrow when I do some 1095 and W-2 together in the same batch that should tell me something, hopefully, LOL.

 

[Willie71]

One thing to consider are the handful of bad pieces of W2 out there. We see reports of problems seveapral times per year. I've been fortunate to have had no bad pieces, but one maker recently showed poor results with one piece, but the other two he tested were fine.

 

[stezann]

You can't quench into those small cans of oil.....you need way more oil volume than that + agitation.
You can compare 2 identical samples in different volumes of the same oil and check the HRC; you will find the minimum amount of oil when you hit the max hardness.

 

[Karl B. Andersen]

I consistently get 67.5 - 68.5 from W2 quenched in Parks 50.

My only problem with W2 is getting it tempered down to a workable "safe" place.
With Parks 50 that stuff gets harder than wood pecker lips.

It's not always steel and/or quenchant, but how you set up the steel post-forging to begin with and how you austenize.

 

[Don Hanson III]

My only problem with W2 is getting it tempered down to a workable "safe" place.
With Parks 50 that stuff gets harder than wood pecker lips.

It's not always steel and/or quenchant, but how you set up the steel post-forging to begin with and how you austenize.

^^^Yes This^^^

Also a thinner cross section will give different results.

When I quench a W2 blade with a 1/4" spine, the spine never fully hardens.

 

[Jeff the Millwright]

I performed the exact same test today on 1095 that I did yesterday on W-2 using different quench mediums. At the prompting of David Stifle I included one sample of W-2 that I again quenched in Houghto-Quench® K to see if my previous test on W-2 in this thread was valid.

Four new test pieces of 1095 and one of W2 to retest in Houghto-Quench® K.

The results:

I think from these results its pretty conclusive that Houghto-Quench® K is capable of hardening 1095 but not W-2. The W-2 and 1095 were both heated to the same Aus temp together and quenched in the same way and 1095 hardened and again W-2 did not.

I am really kicking myself for not having Parks 50 shipped across the border from Texas because although it and Houghto-Quench® K are both rated as 7 to 9 second oil they are not the same and Houghto-Quench® K is inferior or slower anyway.

And on the sample of 1095 that the Houghto-Quench® K was able to harden to 66 it actually had a soft spot in the middle of the sample which wasn’t even in the 50s. So although technically it did quench it to 66 it didn’t do it uniformly. Maybe a bubble developed there possibly I am not sure but I don’t even trust this stuff now for 1095 and really wish I would’ve gotten Parks 50.

 

[Kentucky]

How much quench are you using to quench your test pieces in?

 

[Jeff the Millwright]

I am using 16 ounces for my test pieces and after quenching it didn’t even go up 2°F. My test pieces were only 1” x 0.5 of an inch and if you scale that up to the size of a knife I think it would be like using over a gallon. And that is the same amount of quench oil I used for the 1095 that did harden to 66.