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64 Rc Leek Project Update
- Thread starter Thomas W
- Start date
glockman99
RIP Dann, you were a good guy.
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- Jun 12, 2000
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- 21,269
I have a feeling that up to, or past 65 Rockwell, that the steel would start getting brittle and prone to chipping.
- Joined
- Sep 4, 2004
- Messages
- 1,670
Thanks, Thomas. Sorry to hear things haven't worked out, but credit to you and Kershaw for giving it a try.
Of course I'm not a metallurgist, but from what I'd read it seemed like getting 13C26/AEB-L much over ~61 HRC might require some special finessing, maybe not totally practical in a production environment. In Verhoeven's published work he states that he used "a commercial stainless steel razor strip used in the meat packing industry. The blades are made from Udeholm AEB-L stainless steel heat treated to a hardness of 60 HRC", and the Sandvik datasheet for 13C26 indicates a quenched hardness for the steel of just under 62 HRC (scroll down about 3/4 of the page):
http://www2.sandvik.com/sandvik/014...C6EE1DA60BE49575C125737C007D2B85?OpenDocument
I wasn't able to pin down Cliff's source for the claim that 13C26 can and should optimally be run at 63-65 HRC either, except to guess that maybe it's from Roman Landes. On Cliff's website he posts Landes' heat treat:
# Furnace: Vacuum, protective gas, or salt bath
# Preheat 1: 450-600°C equalize 3-5 min
# Preheat 2: 850-950°C equalize 3-5 min
# Austenize: 1065°C eqalize 3-5min, hold 5min
# Quench: oil preheat to 60°-80°C; N2 4bar
# Cryo 1: immediately after quench min. -70°C or lower, hold 1h
# Temper1: 150°C for 1h, then quench in Water
# Cryo 2: immediately after quench min. -70°C or lower, hold 1h
# Temper 2: 150°-180°C for 1h, then quench in Water
Sounds like it might be pretty expensive.
Anyway, none of this changes my opinion that 13C26 is a great blade steel at practical hardnesses of 59-60 HRC. The Kershaws I have in the steel prove that.
Of course I'm not a metallurgist, but from what I'd read it seemed like getting 13C26/AEB-L much over ~61 HRC might require some special finessing, maybe not totally practical in a production environment. In Verhoeven's published work he states that he used "a commercial stainless steel razor strip used in the meat packing industry. The blades are made from Udeholm AEB-L stainless steel heat treated to a hardness of 60 HRC", and the Sandvik datasheet for 13C26 indicates a quenched hardness for the steel of just under 62 HRC (scroll down about 3/4 of the page):
http://www2.sandvik.com/sandvik/014...C6EE1DA60BE49575C125737C007D2B85?OpenDocument
I wasn't able to pin down Cliff's source for the claim that 13C26 can and should optimally be run at 63-65 HRC either, except to guess that maybe it's from Roman Landes. On Cliff's website he posts Landes' heat treat:
# Furnace: Vacuum, protective gas, or salt bath
# Preheat 1: 450-600°C equalize 3-5 min
# Preheat 2: 850-950°C equalize 3-5 min
# Austenize: 1065°C eqalize 3-5min, hold 5min
# Quench: oil preheat to 60°-80°C; N2 4bar
# Cryo 1: immediately after quench min. -70°C or lower, hold 1h
# Temper1: 150°C for 1h, then quench in Water
# Cryo 2: immediately after quench min. -70°C or lower, hold 1h
# Temper 2: 150°-180°C for 1h, then quench in Water
Sounds like it might be pretty expensive.
Anyway, none of this changes my opinion that 13C26 is a great blade steel at practical hardnesses of 59-60 HRC. The Kershaws I have in the steel prove that.
- Joined
- Sep 4, 2004
- Messages
- 1,670
Devin and Larrin both have a lot of credibility with me, too. I hope Larrin expands on this.
Guess that's one thing steel and theory have in common: to be useful, both usually need to be tempered.
I remain Leekless....I wanted a user, but I guess I'll grab a damascus blade for the "keepers" box.
Thomas W
Banned
- Joined
- Oct 11, 2005
- Messages
- 5,710
It was 64.5 Rc
- Joined
- Aug 13, 2005
- Messages
- 1,283
- Joined
- Jul 14, 2007
- Messages
- 2,837
Not trying to keep kicking a dead horse here, but STR had nothing but great
things to say about the blade you sent out to him for testing back in Feb.
I'm no steel expert by any means, I'm just curious what has happened from the time STR
tested the blade you sent out to him and the scrapping of the 64.5 Leek project.
I'm just asking so please don't put that choke hold on me.
Yeah I know.... " there was never a choke hold".
With that avatar, I'm almost scared to post this.
- Joined
- Jul 14, 2007
- Messages
- 2,837
Still puzzled, but I won't question the coach's word.
I know all these questions on the 13C26 has to be irritating
you. I just have an inquisitive mind. But I do thank you for
you're time and all the great work you guys do at Kershaw. :thumbup:
- Joined
- Mar 6, 2005
- Messages
- 3,309
...Not really Thomas...I know you could move the indentor 2 mm either side of the initial reading and get numbers that can be 1 to 3 points lower at times...It's that "Alchemy" of heat treating...Thanks for hangin' in there ...:thumbup:
- Joined
- Jul 14, 2007
- Messages
- 2,837
Ummm... just a little lol.
But I'm gonna stop kicking this horse around.
That is until you wave your magic wand and
can somehow make it happen.
It's funny, I ran across that old thread by accident.
If I knew now what I didn't then.....I think I would have
refrained from starting that thread and getting everyone
worked up....including myself. Again, thanks for the time
you put into this forum and....... for putting up with us.
- Joined
- Aug 27, 2004
- Messages
- 12,955
Ok, I have debated with myself over posting here again hoping to let this die off because I know thats what Thomas would like but since its taken life again I'll add this. It is some info from longer term use and experience of the harder blade.
Speaking of the harder blades in 13C26. Some seem to think the steel is capable of handling a higher Rc. This may be because of input from experts or so called experts claiming some things that ended up being hard to consistantly achieve but here is my take after using it. First let me say this. I've never had this blade independently tested a second time to see how hard it is off another machine and felt no reason to because if Thomas said it was 64.5 then that was all I needed to know.
The simple fact is I've had this blade a long while and still like it a lot but I've had a chance to get to know it now. This blade, good as it is and much as I like it played out like this. It cuts well for a long time with little light reflection and evidence of dinging or edge rolling and did this in various mediums I cut with it, which as I've said was hemp, cardboard, nylon rope, and hardwoods as well as all EDC jobs any knife I own does including packing and tape cutting even through fiberglass tape which is does well also.
I did a lot of carpet cutting with it yesterday in fact helping a neighbor cut down remenants to throw out in this mornings trash. Just as before I saw less dinging or edge thickness after cutting than I've seen cutting carpet with the SG2, D2 or even some thinner 30` beveled S30V blades and other steels I've cut the same things with but in truth after testing other 'softer' blades at around the 59-60 RC in 13C26 I could say that about all of them I cut with. The stable edge is one of the best things about the 13C26 steel in my opinion. But, and this is the kicker. The truth is after using some of a 52100 steel I got a while back for a folder I built I saw one thing that stood out to me that was similar about both the 52100 and the 13C26 at the higher 64.5 Rc hardness.
Both blades held an edge well, and a thin one at that for quite a while before need of touch up. However, in sharpening the blades both seemed to never quite be able to reach the same level of sharpness or 'bite' as I often call it that other steels we have grown to love do. At first I thought it was the Edge Pro, so I moved to using the Sharpmaker. That didn't work. I just figured these ones to be harder to sharpen but then others noted the same thing about this harder blade I was seeing this with. Then when I used some of Kirk's 52100 and saw the same thing I figured well some steels are just funny I guess.
I'm not a scientist so I don't know what is going on when steels behave this way. I suspect after speaking with folks on it that its retained austentite as the root cause of this trait in both steels but its just a guess. I eventually learned from sharpening both that what I had to do was just figure, "well, I guess thats all she is going to give me for sharp." I accepted what edge she would give me and used it. The good news was that what edge it took it kept for a long time. Don't get me wrong you could get it to bite like we like and at first I thought I was getting it with either the harder 13C26 or the Kirk 52100 blade but what I learned was that they never kept that initial bite, but went back fairly fast to the sharpness level I kept trying to get it a step above yet and then once again would level off there for a good long while. Most end line users would probably like this about the steel because once you get it there it will seemingly keep it but its never going to be the razor blade we all like and seem to get with our ZDP and SG2 blades at this hardness or with whatever is going on in it.
Note this was not dull at all, just not the edge I had earlier. Sometimes On Kirk's blades I got a good initial bite and didn't even use the blades and noted that the edge felt differently than it did right after sharpening it the next time I pulled it out to use it. This seemed to change from just sitting. I began to wonder if the edge oxidized or something as it sat in my pocket. I did some checking and then with some better specs on my eyes to see better I realized with both steels that it was a micro burr giving me the initial bite I was getting. Remove that the bite left, but it cut fine for a long time with the edge it took which again was that same edge that I could never seem to get it to rise above.
As I said, eventually I realized that getting that oh so familar bite with it was just not achievable so I stopped trying realizing that at least with what she would give me she kept it for a long while and I went with that. I still love and use it a lot and as a result of testing other 13C26 took on a whole new respect for it and 12C27. I think both have limits though and unfortunately Kershaw found out some of the facts on that the hard way. Lesson learned now we move on.
What I have learned since then in using the NRG, and some others that are the regular run hardness is that they can take a bite with little burr problem and keep that bite and good edge just fine. It took me a while of using various blades to get this comparison going in my head to see what was going on. One day if I get time I'll reprofile or maybe get a friend to do his magic on another regular hardness one and run it through the paces in hemp, carpet, cardboard boxes and hard woods the same as the harder one and see how it compares thinner at a 59-61 hardness. I expect it to be hard to tell the diff to be honest. Both have proven to be very good for me.
Anyway, thats it for me. I'm tired of discussing it too and you can take this for what its worth. If I have my way its my last post on it.
STR
Speaking of the harder blades in 13C26. Some seem to think the steel is capable of handling a higher Rc. This may be because of input from experts or so called experts claiming some things that ended up being hard to consistantly achieve but here is my take after using it. First let me say this. I've never had this blade independently tested a second time to see how hard it is off another machine and felt no reason to because if Thomas said it was 64.5 then that was all I needed to know.
The simple fact is I've had this blade a long while and still like it a lot but I've had a chance to get to know it now. This blade, good as it is and much as I like it played out like this. It cuts well for a long time with little light reflection and evidence of dinging or edge rolling and did this in various mediums I cut with it, which as I've said was hemp, cardboard, nylon rope, and hardwoods as well as all EDC jobs any knife I own does including packing and tape cutting even through fiberglass tape which is does well also.
I did a lot of carpet cutting with it yesterday in fact helping a neighbor cut down remenants to throw out in this mornings trash. Just as before I saw less dinging or edge thickness after cutting than I've seen cutting carpet with the SG2, D2 or even some thinner 30` beveled S30V blades and other steels I've cut the same things with but in truth after testing other 'softer' blades at around the 59-60 RC in 13C26 I could say that about all of them I cut with. The stable edge is one of the best things about the 13C26 steel in my opinion. But, and this is the kicker. The truth is after using some of a 52100 steel I got a while back for a folder I built I saw one thing that stood out to me that was similar about both the 52100 and the 13C26 at the higher 64.5 Rc hardness.
Both blades held an edge well, and a thin one at that for quite a while before need of touch up. However, in sharpening the blades both seemed to never quite be able to reach the same level of sharpness or 'bite' as I often call it that other steels we have grown to love do. At first I thought it was the Edge Pro, so I moved to using the Sharpmaker. That didn't work. I just figured these ones to be harder to sharpen but then others noted the same thing about this harder blade I was seeing this with. Then when I used some of Kirk's 52100 and saw the same thing I figured well some steels are just funny I guess.
I'm not a scientist so I don't know what is going on when steels behave this way. I suspect after speaking with folks on it that its retained austentite as the root cause of this trait in both steels but its just a guess. I eventually learned from sharpening both that what I had to do was just figure, "well, I guess thats all she is going to give me for sharp." I accepted what edge she would give me and used it. The good news was that what edge it took it kept for a long time. Don't get me wrong you could get it to bite like we like and at first I thought I was getting it with either the harder 13C26 or the Kirk 52100 blade but what I learned was that they never kept that initial bite, but went back fairly fast to the sharpness level I kept trying to get it a step above yet and then once again would level off there for a good long while. Most end line users would probably like this about the steel because once you get it there it will seemingly keep it but its never going to be the razor blade we all like and seem to get with our ZDP and SG2 blades at this hardness or with whatever is going on in it.
Note this was not dull at all, just not the edge I had earlier. Sometimes On Kirk's blades I got a good initial bite and didn't even use the blades and noted that the edge felt differently than it did right after sharpening it the next time I pulled it out to use it. This seemed to change from just sitting. I began to wonder if the edge oxidized or something as it sat in my pocket. I did some checking and then with some better specs on my eyes to see better I realized with both steels that it was a micro burr giving me the initial bite I was getting. Remove that the bite left, but it cut fine for a long time with the edge it took which again was that same edge that I could never seem to get it to rise above.
As I said, eventually I realized that getting that oh so familar bite with it was just not achievable so I stopped trying realizing that at least with what she would give me she kept it for a long while and I went with that. I still love and use it a lot and as a result of testing other 13C26 took on a whole new respect for it and 12C27. I think both have limits though and unfortunately Kershaw found out some of the facts on that the hard way. Lesson learned now we move on.
What I have learned since then in using the NRG, and some others that are the regular run hardness is that they can take a bite with little burr problem and keep that bite and good edge just fine. It took me a while of using various blades to get this comparison going in my head to see what was going on. One day if I get time I'll reprofile or maybe get a friend to do his magic on another regular hardness one and run it through the paces in hemp, carpet, cardboard boxes and hard woods the same as the harder one and see how it compares thinner at a 59-61 hardness. I expect it to be hard to tell the diff to be honest. Both have proven to be very good for me.
Anyway, thats it for me. I'm tired of discussing it too and you can take this for what its worth. If I have my way its my last post on it.
STR
- Joined
- Jan 17, 2004
- Messages
- 5,016
Hi STR, I've done a little bit of testing with AEB-L. I did a concret floor test using 63 Rc without tip damage, using an 8" chef's knife with a tip that was about .011" (not ground all the way for a chef's knife).
I have also seen that AEB-L loses its initial sharpness more slowly than high alloy steel. I don't know the cause of your problems, but AEB-L has always been very easy to sharpen and very easy to remove the burr. A burr will definitely give you high sharpness that you will lose very quickly.
These are both mine and my father's observantions, using knives made with our heat treatment, different knives and different heat treatments will definitely give different results.
I like lots of knives and lots of steels, I hope you keep having fun, even after such a downer as losing this special Leek.
I have also seen that AEB-L loses its initial sharpness more slowly than high alloy steel. I don't know the cause of your problems, but AEB-L has always been very easy to sharpen and very easy to remove the burr. A burr will definitely give you high sharpness that you will lose very quickly.
These are both mine and my father's observantions, using knives made with our heat treatment, different knives and different heat treatments will definitely give different results.
I like lots of knives and lots of steels, I hope you keep having fun, even after such a downer as losing this special Leek.
- Joined
- Jul 14, 2007
- Messages
- 2,837
STR, thanks a lot for this long and thorough reply. What you've just said explained
exactly what I was wanting to know. I work in the carpet industry and trust me I
know what carpet does to an edge. Like I've said, I'm no steel expert. I just know
what works when I have hands on experience. It's the knowledge of seasoned veterans
like yourself and others that I depend on before choosing a certain steel. And I really do
appreciate your time and effort as well as everyone else that put there knowledge and experience
into this forum so we can learn from you. That's why I joined the BF's...
To learn and have fun with our mutual crazed knife addiction.
Again, thanks for explaining this and thank you and everyone else for making
this a fun and educating place to come to. :thumbup:
exactly what I was wanting to know. I work in the carpet industry and trust me I
know what carpet does to an edge. Like I've said, I'm no steel expert. I just know
what works when I have hands on experience. It's the knowledge of seasoned veterans
like yourself and others that I depend on before choosing a certain steel. And I really do
appreciate your time and effort as well as everyone else that put there knowledge and experience
into this forum so we can learn from you. That's why I joined the BF's...
To learn and have fun with our mutual crazed knife addiction.
Again, thanks for explaining this and thank you and everyone else for making
this a fun and educating place to come to. :thumbup: