Steel Edge Retention testing

cds4byu said:
This is why CATRA uses silica-impregnated paper. It dulls knives much more quickly. And if you used the thread-cutting test to measure sharpness, I'd be OK with the use of CATRA media. But I think that the CATRA media actually dulls knives too quickly. It's almost like testing a blade by shaving off part of a sharpening stone.

Hope you get better!

Carl
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I think I am better.

I think my exercise show that there is much more complicated evolution of the blade happen before it got dulled.

For example Busse is total winner if we test how many times it will slice the rope, and skip how long it will keep fine edge. I am absolutely sure that it may slice over 3000 times manila rope and more. But FFD2 keep high edge for quite a long time even at the end it came more closer to other steels.

I think I may just slide edge over some wood without real cutting and this will dull the edge. ASI actually did some research on how background affect rope cutting and found that it does affect it significantly! So I thin I may give up rope and just kind of scratch wood surface instead,

Are you the Carl who coauthor of this FF patents?

If so can you give some metallurgy background to what happen to FF area?

I read some papers about this, but first hands always better source for info. Please, can you give some brief description of what is going on and why?

Thanks, Vassili.
 
Picture from my Busse Game Warden testing. 50 cuts:

testing-15.jpg


Thanks, Vassili.
 
Noz, I like your way of testing, that pic looks interesting.

I think between you and Noss4 we have Cliff Stamp pretty well covered. You do the first part of cliffs tests and Noss does the second part.:thumbup:
 
You could intentionally add some abrasive material to your rope. For example you could soak your rope in some artist's clay or plaster of paris mixed with water. It would probably work best if you used a container with a tight lid and shook the rope and solution for mixing. Remove the rope and let it dry. After this dries you would have rope with grit embedded in the fiber.
 
hmm, more silly questions from me - how large can we let the abrasives get in cutting tests, I think testing would go much faster is I scraped my edges against the driveway :D Now I'm wondering how we define edge wear and damage, and what we cut to dull our knives.
 
I think, hardheart raised the critical question here. We all know that there are two dulling mechanisms at work. If you are adding an abrasive, the test will, no doubt favor the steels with high abrasion resistance and disfavor hard steels with low abrasion resistance that would resist dulling by deformation better.

I guess ideally one would do two types of edge retention testing: On on a very hard material, such as something that is fiber reinforced. And one on something that is very abrasive.
 
I decide to give it another try. I add vacuum cleaner to the test area so it will take away all dust and everything - this actually speed up testing. I also add new steel to test - it is Lauri blade from http://www.brisa.fi out of UHB17VA (C=0.85 Cr=0.54 Mn=0.55 P=0.02 Si=0.3 S=0.02 V=0.2) by Uddeholm (Sweden) it is close to O1 as I understand. It is Progressive tempered and has 63 HRC on the edge - should be similar in some sence to Friction Forged D2. Only difference that this blade cost 13.60 eur...

I managed to sharpen it even better than DiamondBlades - once they proved that it is possible I was able to do this too - I use 0.15 micron diamond powder after Green Rouge and have it even bit sharper:

FF D2
10 +++
20 +++++++X++
30 ++++++
40 ++

PT UHB17VA
10 ++
20 ++++++++X+++++
30 +++++

You may see that median ('X') is in the middle of 20th for PT UHB17VA while it is near 30th for FF D2.

I like to compare FF D2 with other steel at it's high hardness.

Thanks, Vassili.
 
I have been following this thread with great interest. Thank you Vassili for a great job.
The steel in Lauri PT is not an Uddeholm steel, but made in Germany by ThyssenKrupp. The steel composition is as you describe though. The tempering process is developed by Juha Perttula, doctor in technology at Tampere University in Finland.

best regards Dennis
 
Dennis H said:
I have been following this thread with great interest. Thank you Vassili for a great job.
The steel in Lauri PT is not an Uddeholm steel, but made in Germany by ThyssenKrupp. The steel composition is as you describe though. The tempering process is developed by Juha Perttula, doctor in technology at Tampere University in Finland.

best regards Dennis
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Hi Dennis,

I saw this composition on your site and manage to find in the web only UHB17Va which match this composition, so this is why I called it this way. Do you know exact steel name?

Thanks, Vassili.
 
How does a Damascus blade compare to other good knife steel? Edge holding? Strength? Corrosion resistance?

It looks nice, but how's it hold up?
 
it depends on the steels that compose it, if you are talking pattern welded. If you mean carbide segregated steels, the composition can vary as well. Asking about 'damascus' steels is sorta like asking about 'stainless' or 'tool' steel, you gotta be more specific.
 
hardheart said:
it depends on the steels that compose it, if you are talking pattern welded. If you mean carbide segregated steels, the composition can vary as well. Asking about 'damascus' steels is sorta like asking about 'stainless' or 'tool' steel, you gotta be more specific.
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I'm not too familiar with the multitude of steels so I'm trying to learn a bit more... I've found a number of threads which have been helpful (including this one). I've looked at a Kershaw Leek in 1660 Dam. for example, and note that it is also available in "regular" 1660, and S30V. Can I assume that there is little dif. between the 1660 Dam. and the "regular" 1660? Looks aside, would the two be the same as far as strength, edge holding etc.?

I appreciate your insights and expertise.
 
timcsaw said:
I'm not too familiar with the multitude of steels so I'm trying to learn a bit more... I've found a number of threads which have been helpful (including this one). I've looked at a Kershaw Leek in 1660 Dam. for example, and note that it is also available in "regular" 1660, and S30V. Can I assume that there is little dif. between the 1660 Dam. and the "regular" 1660? Looks aside, would the two be the same as far as strength, edge holding etc.?

I appreciate your insights and expertise.
Click to expand...

Usually if you have such question you ask it in separate thread - it is about "Steel Edge Retention testing". If you read posts here you may have idea what it is about.

In general "plywood" blades does not show better performance, I may even say they did not show even good performance. But again it is different topic.

I will test eventually Bulat which is called also Damascus steel or True Damascus or Wootz.

Thanks, Vassili.
 
1660 is the model number for the Leek, not the steel used in it. All I've read is that the damascus is made in Alabama, by the same company that does it for Bear and Sons. Alabama Damascus has an ebay store, and a broken website, lol.

Pattern welded steel, like the one in the Leek, is composed of two or more steels layered and heated together. It is then forge welded under impact/pressure. The billet is twisted/folded in a variety of ways to create the patterns. The pattern is made visible by polishing and etching, the light and dark bands caused by the different compositions. For instance, in an O1 and L6 damascus, the L6 has a lot of nickel, so it creates the bright bands.

Back to the main topic-I really want to see such a test done with the same steel at different hardnesses. Like maybe just old 1095 in a handful of blades from 56 to maybe 62 Rc. Something like that would give a better indication of how hardness effects edge retention. I wonder how the ATS would have done if it was 57 like the 420HC.
 
hardheart said:
1660 is the model number for the Leek, not the steel used in it. All I've read is that the damascus is made in Alabama, by the same company that does it for Bear and Sons. Alabama Damascus has an ebay store, and a broken website, lol.

Pattern welded steel, like the one in the Leek, is composed of two or more steels layered and heated together. It is then forge welded under impact/pressure. The billet is twisted/folded in a variety of ways to create the patterns. The pattern is made visible by polishing and etching, the light and dark bands caused by the different compositions. For instance, in an O1 and L6 damascus, the L6 has a lot of nickel, so it creates the bright bands.

Back to the main topic-I really want to see such a test done with the same steel at different hardnesses. Like maybe just old 1095 in a handful of blades from 56 to maybe 62 Rc. Something like that would give a better indication of how hardness effects edge retention. I wonder how the ATS would have done if it was 57 like the 420HC.
Click to expand...

Sorry about the digression from the OP. I do appreciate the schooling!!

To the OP... I don't see any edge tests on Dam. steel. Will this be addressed? I will keep my eye on the thread.

Thanks again!
 
Finally i finished Friction Forged D2 testing. It shows best result in my tests all over scale, it is better on high sharpness and small load as well as at 800 cuts.

I like to test ZDP189 and see how it will be against Friction Forged steel as well as CPM 10V. But for now Friction Forged D2 by DiamondBlade is the best in my tests.

Here I tape part of the testing from 765 to 770 cuts, it now, with vacuum machine, goes much faster.

http://www.youtube.com/watch?v=O8_C7jV_gI4

Thanks, Vassili.
 
Vassili, I think you have the Tyrade listed as SG2, shouldn't it be D2?

Have you had any luck getting hold of an SG2 JYD II? Considering how sharp mine was out of the box, I'd be interested to see your results.
 
kneedeep said:
Vassili, I think you have the Tyrade listed as SG2, shouldn't it be D2?

Have you had any luck getting hold of an SG2 JYD II? Considering how sharp mine was out of the box, I'd be interested to see your results.
Click to expand...

Thanks, I fixed it. Sure I'll update that page with any new knife.

Thanks, Vassili.
 
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