Stroke Direction

[wickededge]

Some Faith Restored! 🙂

I’ll post a whole write up soon, but for now I’ll leave the following: I took a blade up through 10k Chosera and then on to the .25um kangaroo strops. At 10k it wasn’t really popping hairs in the hanging hair test, but after the roo strops, it was consistently returning values of HH4 and HH5 (reference here). From there, I took it to the sharpness tester and got great results: 34% less force than with the 100# plates.

-Clay

[Daniel maloon]

I was about to start to sharpen knives on cinder blocks haha

[wickededge]

Here’s a nice micrograph of the 10k>.25um blade:

10k Choseras> .25um Diamond on Kangaroo Strops – 2000x

I wasn’t trying for perfection with the strops and only did about 20 strokes per side. It’s always fascinating to me how quickly the convex shaping happens with the strops, especially considering that I lowered the angle by 1 degree and the leather on the roo strops is very thin. The big scratch in the blade measures 3.66um at the widest point.

Attachments:

• hd320517.jpg

-Clay

[wickededge]

Went ahead and took things a step further. I went back through the Chosera stones from 2k>3k>5k>10k and then on through .25um diamond on roo to .125 CBN on roo. This time I lowered the angle by 2 degrees before stropping. I did the hanging hair test at each level. Here are my results:

2k Chosera = HHT Fail
3k Chosera = HHT Fail
5k Chosera = HHT Fail
10K Chosera = HHT Fail
.25um Diamond = HHT3-HHT4
.125um CBN = HHT4-HHT5

This sounds like it could be a negative review of the Chosera stones, but it really is not. The reality is that they quickly and easily allowed me to take an edge that had been experimented on for two days with a huge variety of stones and transform it into a cutting superstar. Once I got them to the 10k level, taking the step further with the strops was a breeze and only required a few strokes. Here is a nice picture of the edge all cleaned up:

10k Choseras> .25um Diamond on Kangaroo Strops> .125 CBN on Kangaroo Strops – 2000x

On Monday I’ll run it through the sharpness testing jig and see what kind of results I get.

Attachments:

• he78af2d.jpg

-Clay

[Phil Pasteur]

Some Faith Restored! 🙂

I’ll post a whole write up soon, but for now I’ll leave the following: I took a blade up through 10k Chosera and then on to the .25um kangaroo strops. At 10k it wasn’t really popping hairs in the hanging hair test, but after the roo strops, it was consistently returning values of HH4 and HH5 (reference here). From there, I took it to the sharpness tester and got great results: 34% less force than with the 100# plates.

I think that is why I wrote “more to come”..
Very interesting.. and faith being restored by the test..

I love the Chosera stones to 10K as a base for getting “super” edges…

[Josh]

Wow! I can definitely see a difference in the second picture where you tried harder 🙂 much crisper and cleaner! That is nice!

[Phil Pasteur]

bottom line is..it looks like sharp is starting to show up as sharp…

👿
😆

😛

[Josh]

Clay, how many passes did you do at the .25 and .125 strops? just curious…

[wickededge]

Clay, how many passes did you do at the .25 and .125 strops? just curious…

That was after a total of 70 strokes per side. I’ll go ahead and do some more stropping and see what kind of improvement I get.

-Clay

[Leo Barr]

One thing I have missed is what type of steel are you using for these tests I have read that the latest wonder steel is hap40 a powdered steel from Hitachi with a possible rockwell hardness of 68 this steel I have read has incredible edge retention capabilities so much so someone nicknamed it voodoo steel since it holds an edge so well!
I think the work is most interesting sharpening techniques must have different results on different steels would they not .
Early days I am sure but these Hitachi super steels must respond differently when sharpened to say the steel of Henkels or Worstoff .
I wonder if there is less of a need for extensive stropping on these super steels would not the whole appearance of these super hard steels have a much finer appearance under high magnification therefore producing a far finer edge.(say at a near molecular level would the steel be closer knit I would expect say a poor quality steel to have more impurities therefore a less dense structure)
This is pure speculation on my part with a very basic knowledge of metallurgy & chemistry.
Perhaps your test will bear this out.

[wickededge]

This is slightly off-topic but concerns the same blade I’ve been working with. I went ahead and spent more time erasing the majority of scratches with the .25um diamond and .125um CBN on kangaroo strops. Here is a nice picture of the blade at 2000x:

.125um CBN on Kangaroo Strops – 2000x Magnification

I ended up increasing the angle a little, coming back to one degree less than what I’d been using for the stones. The slight convex shaping that occurred is easy to see and the resultant loss of cutting performance was easily detected with the hanging hair test. The blade went from easily scoring HHT5 to scoring HHT4 with the occasional HHT5. Clearly that slight bit of rounding of the edge is something to keep in mind when finishing a blade, especially when pursuing a mirror polish. I think we’ll get a separate post going about what one’s goals might be in stropping.

Attachments:

• hc592577.jpg

-Clay

[wickededge]

One thing I have missed is what type of steel are you using for these tests I have read that the latest wonder steel is hap40 a powdered steel from Hitachi with a possible rockwell hardness of 68 this steel I have read has incredible edge retention capabilities so much so someone nicknamed it voodoo steel since it holds an edge so well!
I think the work is most interesting sharpening techniques must have different results on different steels would they not .
Early days I am sure but these Hitachi super steels must respond differently when sharpened to say the steel of Henkels or Worstoff .
I wonder if there is less of a need for extensive stropping on these super steels would not the whole appearance of these super hard steels have a much finer appearance under high magnification therefore producing a far finer edge.(say at a near molecular level would the steel be closer knit I would expect say a poor quality steel to have more impurities therefore a less dense structure)
This is pure speculation on my part with a very basic knowledge of metallurgy & chemistry.
Perhaps your test will bear this out.

Leo, the blades I’m using are ‘high carbon’ utility blades. I like them because I can buy them in bulk and they’re quite consistent, making it easy to compare edge geometries and finishes side by side.

-Clay

[Phil Pasteur]

I ended up increasing the angle a little, coming back to one degree less than what I’d been using for the stones. The slight convex shaping that occurred is easy to see and the resultant loss of cutting performance was easily detected with the hanging hair test. The blade went from easily scoring HHT5 to scoring HHT4 with the occasional HHT5.

Interesting Clay, but not unexpected I guess.
Did you do any tests with the sharpness tester to see if the changes in the HHT correlate to anything measureable with that device?

[wickededge]

I ended up increasing the angle a little, coming back to one degree less than what I’d been using for the stones. The slight convex shaping that occurred is easy to see and the resultant loss of cutting performance was easily detected with the hanging hair test. The blade went from easily scoring HHT5 to scoring HHT4 with the occasional HHT5.

Interesting Clay, but not unexpected I guess.
Did you do any tests with the sharpness tester to see if the changes in the HHT correlate to anything measureable with that device?[/quote]

I didn’t get to the sharpness testing machine today but definitely will tomorrow.

-Clay

[Josh]

This is slightly off-topic but concerns the same blade I’ve been working with. I went ahead and spent more time erasing the majority of scratches with the .25um diamond and .125um CBN on kangaroo strops. Here is a nice picture of the blade at 2000x:

.125um CBN on Kangaroo Strops – 2000x Magnification

I ended up increasing the angle a little, coming back to one degree less than what I’d been using for the stones. The slight convex shaping that occurred is easy to see and the resultant loss of cutting performance was easily detected with the hanging hair test. The blade went from easily scoring HHT5 to scoring HHT4 with the occasional HHT5. Clearly that slight bit of rounding of the edge is something to keep in mind when finishing a blade, especially when pursuing a mirror polish. I think we’ll get a separate post going about what one’s goals might be in stropping.

Ok, I just read this again and the other post is no fair… you have to take new photos lol. Man, I love seeing what happens on a microscopic level! It really makes sharpening come alive and allows us to achieve optimal sharpness based upon our research here. This is one thing that totally makes the WEPS shine… not only the support and on-going research, but what other system can you create a perfect bevel and then lower it 2*/side precisely when you move to strops? Of course you can w/ the Edge Pro, but its not conducive to that system (since you would have to “pull” the arm toward you with each pass after you custom mount the strop that is =)

going to have to re-think my straight razor strategy… I haven’t been lowering the angle because I wanted the edge to be sure to be hit to erase all of the prior scratches, but clearly that is not the case and is not achieving optimal sharpness for my purposes.

[Author]

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