Hey guys i have been using s35vn 440c damasteel and other stainless Damascus even used vanax but i just cut 2 folding knife blades from elmax. i have seen the spec sheets and different heat treat charts that are out there so i have a good idea of how to get it to different hardness but no where did i find a "target" harness some steels work better than others at certain hardness so i am wondering what my target should be for these 2 folders. Has anyone used this steel and tested it and figured this out? any info/advice would be appreciated!

No actual info here other than I’ve got a couple of knives with elmax blades and they sure are tough. Good for you for using a premium steel. 

Hardness needs to align with the alloy; but it needs to align with the intended use and the personal preferences of the user too. There is not *1* hardness to be strived for.

Personally I HATE knives that take a diamond hone to sharpen.  Others LOVE them; what is the correct hardness then?

yeh your right the harde you make them the longer it will hold its edge but when you do sharpen its harder to sharpen if the steel is softer it will be easy to sharpen but you will have to do it mor often....usually there is kinda of a window not a exact target like say 60.2 but from 1 steel to another one may have peek toughness and performance higher at say 60.5-61 others may be at 59.....i have a hardness testeer so i can use that to know the exact hardness and ill just have to test the blades at different hardness levels to see how they re act (same thing i did in the past for s35vn)

Do you have access to a Charpy test rig too? (so you can work with hardness and toughness to get  to the  point you like!)

never even herd of a charpy test rig..

measures toughness

i just google it and well it seems you either drop a ball and let it hit the steel from a certain height or a ball swings  on a penjulum to hit the steel....from the pics and video i saw what they were using would have to be heavily modified for our uses do you have any links to any info on how to make one or are there rigs out there to buy cheap enough...not going to buy or start making one today but deffinitly need to get more info on the subject

You could also figure out your own method of judging toughness.  I'm trying to keep people aware that there is more than just hardness when evaluating a blade steel.

Knowing you can check for Charpy results at various tempers and alloys.

I saw my first Charpy test in a Materials Science class back in the late 1970's. It used a swinging weight released from a set height and then measured how far it traveled after breaking the sample and then had a conversion factor to how much energy had been used in breaking the sample---so all the samples had to be identical in shape.

Chirpy is a laboratory test that requires one independent variable for the scientific method -in this case, amount of energy lost in striking  the sample is the independent variable.  I once read a master's thesis for a metallurgist wherein more than 800 samples were tested.   As you know, toughness is the resistance to tearing.   Thomas is right - hardness is only one thing to consider.  When selecting blade steels, how the blade is to be used should drive the steel choice using hardness, toughness, strength, ductility, corrosion resistances , etc should be part of the steel selection process. 

Put simply:

• Strength measures the resistance of a material to failure, given by the applied stress (or load per unit area) 
• Toughness measures the energy required to crack a material; it is important for things which suffer impact
• Increasing strength usually leads to decreased toughness
• Tempered steel is tougher but less strong than after quenching.

another form  of testing is the Jominy test  http://wmtr.com/en.jominyend.html just to round out your knowledge base. The Jominy End Quench Test ASTM A 255 measures Hardenability of steels. Hardenability is a measure of the capacity of a steel to be hardened in depth when quenched from its austenitizing temperature.

 

Steve thank you for the reference.

I have bookmarked it for future reference.

SLAG.

 

Thanks every one...What i have always done is when i use a new steel i follow the spec sheet and go to a target of around 60 and of corse check with my hardness tester then i finish out the knife (fairly quickly as it will not be sold its a test) i will then first i use the knife AS A KNIFE SHOULD BE USED!!!! cutting carboard rope all sorts of things the whole time i am keeping track of ecxactly how much i am cutting and noting how the knife dulls... after that what i do is ABUSE the knife...now as makers we all know what a knife should be used for and what it shoudnt but i think we also know that some of our customers will not listen to us and they will start battoning a small knife through something or use the tip as a pry bar....Ok i blame forged in fire for this i even had a customer take a fixed blade i made and he went and bought a big brass bolt and layed the edge on the bolt and took a hammer to the spine!! then he wanted to know why the edge got messed up!  so yeh after i do real world tests i abuse it and see how much it will take... depending on how things perform if i started at a hardness of 60 i will make another at a 61 or 59 and repete the tests, after i find where a knife has a good hardness AND holds up best for my testing then my heat treat gets adjusted to make that knife again.. some times i play with things another maker gave me a tip for s35vn that involves quenching in oil till black then hanging it in a pipe with a seam in it length wise (like a vent pipe) and blowing air through that seam that work great...  i usually start with a hardness of 60 unless the spec sheet hints to something different but i had read with this steel it should be slightly lower but it didnt say how much lower ill just do what what i have been doing its worked good so far

Or you can send it to me, as an unrepentant abuser of knives I will happily apply all kinds of unintentional destructive testing to your work...

haha Charles i may just take you up on that offer....i am actually curious as to how SOMEONE else besides me really works it hard i have only sold and gifted a couple of folders and no one has complained i use mine the first one i carried i beat up the second one not so much its got moku ti  and a beautiful dama steel  blade i like it to much. I did send one of my knives to a guy that has been helping me from day 1 knife making and he said it was very solid and well constructed coming from him that means a lot ....but he only had a day or 2 with it so he didnt beat it up that much....like i said i beat one up and i think its solid but would like some one else to do so as well....you may be getting a message from me Charles when the next batch is done :-)

Charles; you going to whittle an anvil from a 3' D2 cube with it?

Well as I have a 3” hunk of A15...