Super Hard (70 Rc) High Speed Steels – Maxamet, Rex 121, and More Explained

High cost, low toughness, difficult to finish and sharpen, and low availability are some reasons. They are not for the average knife user.

Hoss

I killed a bandsaw blade cutting annealed Rex121.
 
Nope you are correct. W2 and 52100 have half the edge retention of 440C, so Z-Wear is probably at least twice as good.

In my experience 52100 and W2 hold an edge better than 440c. I know 440c has more Cr carbide which would contribute greater wear resistance but I believe finer grain structure, higher toughness/hardness of W2/52100 can lead to better edge retention overall?
 
In my experience 52100 and W2 hold an edge better than 440c. I know 440c has more Cr carbide which would contribute greater wear resistance but I believe finer grain structure, higher toughness/hardness of W2/52100 can lead to better edge retention overall?
Sure, 440C will be more wear resistant than 52100 if hardness geometry and sharpening are the same and we are talking slice cutting.
52100 will out cut 440c at higher hardness, more acute sharpening, and with push cutting.

Hoss
 
I love Rex 121, Just wish It loved me back :p
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Very painful to make knives out of.

Hardest, most wear resistant steel I've used.
Beat Maxamet at 70rc and 15V at 67rc in cut testing 3/4 rope by a good margin so I'll keep suffering, stuff works great for advanced users.

Hardest Steel I ever tested was this piece of Rex121 at 71rc

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It really depends on how and what you're sharpening with and what media you're testing with and how.

For me Rex 121 stayed the sharpest a(200g BESS) after cutting a 100 pieces of 3/4 Manilla rope with 8 slices each cut with the least amount of weight possible to slice.

The simple carbon steels wore smooth around 30-50 cuts in other tests.

The rope is to simulate animal hide although the hide and fur can be a lot more abrasive.

Wayne originated the test, Maynard Meadows improved it and Phil taught me his way he learned from them and further modified. I Run a simliar test but I just run to 100 and see what is sharper at the end and look at the rate of dulling using these tools.



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I really enjoyed this one, as these are steels I am quite interested in, and have a few to play with.

Chuck is sending me some z-max to try. I think it’s very similar to Maxamet, so I’ll send some samples in for testing.

I have a question on wear resistance. I see double the edge retention from W2 or 52100 compared to z-wear, at typical hardness levels. Maxamet to 440c seems a bit under represented in terms of improvement at 2.2. (Iirc.) Am I talking about something different?
 
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Show us your testing and your results.

Hoss
And if I do that you will say that it is not valid and you will find million reason for that .......? Why not other way ? Show me the proof that I m wrong ?
 
High cost, low toughness, difficult to finish and sharpen, and low availability are some reasons. They are not for the average knife user.

Hoss
May I add ......................It is difficult to heat treat them in , you know what :)
 
Sorry, Natlek but Hoss has probably forgotten more about knife making than you will ever know.
Maybe.........but probably I spend more time outdoor then he spend in his shop making knives.....
If there is steel I know it is 440C..........I used it and see used by many here all my life .
 
Sorry, Natlek but Hoss has probably forgotten more about knife making than you will ever know.
Did you read my post ? That Catra test data is almost of no use to us .They test edge geometry not steel .What I say is that with same geometry 440C vs HSS , when 440c will lose it s WORKNIG sharpness will get real dull very fast .With HSS that will not happen , HSS will stay in that working sharpness for loooong time .........
 
Sure, 440C will be more wear resistant than 52100 if hardness geometry and sharpening are the same and we are talking slice cutting.
52100 will out cut 440c at higher hardness, more acute sharpening, and with push cutting.

Hoss
Is this what Catra do ? They test different knives with different hardness , different geometry ? What use we have from data like that ? So IF 440C ..............and IF 52000 ......winner is WHO ?
 
Did you read my post ? That Catra test data is almost of no use to us .They test edge geometry not steel .What I say is that with same geometry 440C vs HSS , when 440c will lose it s WORKNIG sharpness will get real dull very fast .With HSS that will not happen , HSS will stay in that working sharpness for loooong time .........
Please stop making stuff up.
 
Please stop making stuff up.
Are we are on same page or it is my English again ?
This is your words ...........
The tester uses a fixed load, test speed, and stroke length. A typical test for a plain edge steel knife is 60 cuts with 50N load at 50 mm/s, which takes about 15 minutes [1]. The test is often used to compare different steels to determine the edge retention potential of each. However, the CATRA tester is not necessarily a device that compares steels; it compares knives. What I mean by that is that the edge angle, how the blade was sharpened, etc. all affect the measurement. Only if all of those variables are kept the same can steels be compared. Even then there is the possibility that with a different set of variables two steels may behave differently. In other words, a knife with a very thin finely polished edge may show Steel A is better than Steel B, but that may be reversed with a thick edge that has a coarse finish. We won’t know for sure until we do the test.
 
Please stop making stuff up.
Do you ever used knife from HSS steel and which one is that ? I have maybe more then 50 of them right now and around 30 give to friends ..most of them are hunters .Some are from M series some from T series HSS steel...so I making stuff ?
 
Do you ever used knife from HSS steel and which one is that ? I have maybe more then 50 of them right now and around 30 give to friends ..most of them are hunters .Some are from M series some from T series HSS steel...so I making stuff ?
I'm eagerly awaiting the side-by-side comparison the hunters made between 440C and high speed steel with controlled variables.
 
I'm eagerly awaiting the side-by-side comparison the hunters made between 440C and high speed steel with controlled variables.
Controlled varibales........ that is what your father will say to me if I show how I do my test .............game which will proof nothing !
Look , this is how I learn...................see this two blanks ? They are cut from same saw , edge of both was line between them before i cut them .So same hardness , same grain structure ................So I can play with geometry , final grit sharpening ...blabalabala and see by my self how that affect without worry about HT....Hrc...Grain ...etc . And that is best way to get some REAL data . If you know better way show me I and i will try that ..
This is 3mm. thick M2 HSS
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