Sharpening high hardness and wear resistant steels

[Steel_Drake]

Good info Dave. Thanks Bodog, darndest thing, the other last few comments I can't read because of the handy, dandy ignore button.
Hopefully no new readers are being led astray, read with care.
Russ

I am happy to let the video evidence I already posted in this thread stand for itself in contrast to the behavior that has followed.

 

[BluntCut MetalWorks]

Steel_Drake - thanks for posted the video: sigma power select II sharpens a ceramic knife. You made good points along with unfounded/untested claim on that stone can effectively abrade any steels regardless of carbide volume. VC is harder than SiC and AO ceramic. When SiC abrasive is small enough, excavate/plow component of sharpening is drastically reduce against steels with high VC volume. I indirectly mentioned in my previous posts about SiC belts are ineffective against 10V when SiC grit size higher than 320. Actually SiC belts 120-220 dies really fast against 10V too because SiC is highly friable, so after a few revolutions, an almost pure thick (think, multi-thin layers if you will) SiC layer totally glass smooth. Sure, stone will release more abrasive but when abrasive is much softer than target(vc), well can't shape those target!

Russ/mycough spoke from quite a bit experience with sharpening high alloy, especially high carbide volume steels. We are here to learn from each-other, no one try to one-up. The more you learn & know, the less you know & much more need to learn - speaking for myself, I reckon!

 

[Steel_Drake]

Bluntcut,

I'm aware that VC is harder than SiC, however I was under the impression that a highly friable SiC benchstone should expose fresh abrasive quickly enough in use to continue cutting effectively, without the problem of quickly wearing out like SiC belts appear to.

Also, I'm not sure if I'm understanding you correctly, but to clarify, are you saying that a steel with a high vanadium carbide volume such as 10V is harder to grind than a ceramic knife? If so, would you happen to know any reasonably priced commercially available knives made with a steel with a high enough carbide volume that I could buy one and try sharpening it on my SiC waterstones? Would a Spyderco Manix LW in s110v have enough vanadium to test this? Or would I need a knife in 10V specifically?

Worst case scenario, assuming your prices are reasonable, I'd be willing to buy one of your customs in 10V just for the purpose of testing out which of my sharpening stones can successfully sharpen it in a reasonable time frame, and to make a video of the results. I've often found that with sharpening knowledge there is no alternative for simply trying something yourself to see what will happen.

 

[Chris "Anagarika"]

Steel Drake,

Totally agree that sometimes it's only by trying one gets it. Not all cases but surely sharpening is one.
Besides, you get a very good knife by buying BCMW 10V.

 

[BluntCut MetalWorks]

For testing - any steel with 4+%V will suffice but higher V% makes it easier to observe result.

Kudo on your willingness to test & verify :thumbup:

In my video, I mentioned using 800 SiC to clean/smooth the bevel, especially my 800 grit SiC shed abrasive very readily (i.e. soft / weak binder stone). The different between mine your SPSII probably abrasive density/concentration. What is this 'clean/smooth' action mean? To me - it means lapping action, where mud/loose-abrasive abrade away matrix in gap between carbide. Of course, when dug deep enough some carbide will drop out.

When lapping 10V,S90V,S110V,S125V,Rex121,etc... with 600+ SiC/AO, the blade/bevel surface will be smooth but mated in appearance - aka carbide haze.

If you only want to one-time test sharpen high vc steel, I can send you a 68rc 10V blade (quite raw with small scandi-like bevel, no handle of course) to try then send back. otoh, sharpeningnut should owns at least 1 or more knife with vc volume > 12-14% (about s30v and up). Also a 64+rc blade will response quite differently than sub 61rc blades, even for low alloy steels. e.g. noticeable diff in sharpening between aebl 60rc and 64-65rc especially when using grit > 1K.

Bluntcut,

I'm aware that VC is harder than SiC, however I was under the impression that a highly friable SiC benchstone should expose fresh abrasive quickly enough in use to continue cutting effectively, without the problem of quickly wearing out like SiC belts appear to.

Also, I'm not sure if I'm understanding you correctly, but to clarify, are you saying that a steel with a high vanadium carbide volume such as 10V is harder to grind than a ceramic knife? If so, would you happen to know any reasonably priced commercially available knives made with a steel with a high enough carbide volume that I could buy one and try sharpening it on my SiC waterstones? Would a Spyderco Manix LW in s110v have enough vanadium to test this? Or would I need a knife in 10V specifically?

Worst case scenario, assuming your prices are reasonable, I'd be willing to buy one of your customs in 10V just for the purpose of testing out which of my sharpening stones can successfully sharpen it in a reasonable time frame, and to make a video of the results. I've often found that with sharpening knowledge there is no alternative for simply trying something yourself to see what will happen.

edit to add: Chris, I agree:thumbup: and thanks.

 

[Chris "Anagarika"]

Luong,

Now I feel a vacuum in 64+ high VC
Gotta be decisive next round BCMW open sale ...

 

[bodog]

Haha, I was just playing a little with Steel Drake. My apologies if you took it seriously.

Luong, have you tried 15V? I've been using a knife with that steel at about 64 RC and it's not been disappointing. I'm actually pretty happy with it but I haven't been really hard on it, either. It's supposed lack of toughness has me being probably a little easier on it than I need to be.

I also have some K390 blades laminated with a 440C type alloy. They're supposedly around 63-64 RC but with the laminate I don't think the hardness can be tested easily. If you want I can trade you a different 15V blade or one of the laminated K390 blades (mirror polished) for one of yours so we can both try something new.

 

[HeavyHanded]

Luong,

Now I feel a vacuum in 64+ high VC
Gotta be decisive next round BCMW open sale ...

Same here, the few samples of steel in this range that I currently have are lonely...

In my experience, most watertsones will sharpen up about the 1k range. I'd certain from reporting, though I don't own the SPSII, that they grind these steels faster, I'd have to see for myself them bringing high VC to a good outcome at higher levels of polish. Other high carbide steels is easier to believe.

Once the abrasive size gets down to 20 micron or so (10% abrasive actually proud of the binder/surrounding field) the carbides wear resistance kicks in. SIC does have advantage of high friability, myself I have not seen it perform optimally on high VC to high polish compared to a super abrasive. I have gotten good results with it, but not great.

 

[Steel_Drake]

Luong,

I just remembered that Spyderco currently has a mule team blade in Maxamet at somewhere between 67-71 HRC, which should cover both the vanadium carbide volume and high hardness aspects required for this test. I'd been curious about trying something in maxamet anyway, so I think that will be the option I go with for this test unless someone convinces me otherwise.

Edited to add: For what its worth, CPM-M4 has the 4% vanadium you mention above and I have no issues at all sharpening it on SPS-II stones . Actually for that matter I don't have an issue using my King 1000 on my knives in CPM-M4, ZDP-189, and HAP40 either actually.

 

[BluntCut MetalWorks]

Buy Now = ((7/3)*pie*want^3)/need. My Burl.BN is right around 9999.9 (99.999% of the time)

Luong,

Now I feel a vacuum in 64+ high VC
Gotta be decisive next round BCMW open sale ...

 

[BluntCut MetalWorks]

Knowing what you do with knives, even a Graphenon_Kevlarium knife wouldn't last 1 round.

I haven't try 15V yet. 15V looks like a heavy champ in cold work wear resistant, while rex121 on hs. I've tested rex121 at a few different hrc. ~67-68 seem most stable but it lose dry-shave sharpness with very low lateral forces. I think 15V might be a little worse because its MC is mainly in VC form, vs rex121 has higher mixture of alloyed-carbides. I have some experience with ht & using k390. k390 was ht-ed with std and cwf. IME with std ht k390, it's quite stable at around 64rc but need to avoid cuts with moderate lateral force. 65+rc cwf ht k390 is good and can use with closed eyes w/o worry about micro chipping on moderate lateral forces. I only have 1 k390 blank and not easy getting more, so 10V got an easy win on availability factor.

I appreciate the idea of cross eval knives. My interest for 15V would be std vs cwf ht at various hrc - In a bar form probably(when time come, I will contact NSM). Please email me about 68rc 10V unfinished blade.

Haha, I was just playing a little with Steel Drake. My apologies if you took it seriously.

Luong, have you tried 15V? I've been using a knife with that steel at about 64 RC and it's not been disappointing. I'm actually pretty happy with it but I haven't been really hard on it, either. It's supposed lack of toughness has me being probably a little easier on it than I need to be.

I also have some K390 blades laminated with a 440C type alloy. They're supposedly around 63-64 RC but with the laminate I don't think the hardness can be tested easily. If you want I can trade you a different 15V blade or one of the laminated K390 blades (mirror polished) for one of yours so we can both try something new.

 

[BluntCut MetalWorks]

Nope/nah - one is enough, unless BN grabbed hold of you as well

Your question in previous post ~rephrased~ about can't shape the apex w/o shape carbides as well. You've extensively tested SiC (pure & mixed) compound, 'optimal' is elusive when carbide volume & type are moving goal post. Even with diamond/cbn abrasive, cut/abrade rate of matrix is faster than carbide. Therefore in order to optimally shape the apex loaded with vc, best to use fixed-abrasive on hard flat surface and where abrasive cutting points doesn't dislodge carbide due to impact.

Same here, the few samples of steel in this range that I currently have are lonely...

In my experience, most watertsones will sharpen up about the 1k range. I'd certain from reporting, though I don't own the SPSII, that they grind these steels faster, I'd have to see for myself them bringing high VC to a good outcome at higher levels of polish. Other high carbide steels is easier to believe.

Once the abrasive size gets down to 20 micron or so (10% abrasive actually proud of the binder/surrounding field) the carbides wear resistance kicks in. SIC does have advantage of high friability, myself I have not seen it perform optimally on high VC to high polish compared to a super abrasive. I have gotten good results with it, but not great.

 

[BluntCut MetalWorks]

IME/IMO, King1K stone is ineffective in shaping VC in m4 & hap40. I sometime use King800 to create carbide haze surface, so w/o much doubt - the steel surface was lapped (inset matrix, proud carbides).

With M4 or Hap40, sharpen 15dps to dry-shave using SPSII vs DMT EF. Slice phonebook paper 10 times, whittle some pine. Which one has higher keenness (thinner apex radius)?

If that test is inconclusive ...
67+rc maxamet would be an excellent candidate for gain experience with sharpening high + hard alloy steel.

** keep in mind - depend on steel composition, vc could mean this particle is mostly vanadium+carbon but can be composite & clumped-up with other elements/particles such as W, Cr, Mo, Nb. **

Luong,

I just remembered that Spyderco currently has a mule team blade in Maxamet at somewhere between 67-71 HRC, which should cover both the vanadium carbide volume and high hardness aspects required for this test. I'd been curious about trying something in maxamet anyway, so I think that will be the option I go with for this test unless someone convinces me otherwise.

Edited to add: For what its worth, CPM-M4 has the 4% vanadium you mention above and I have no issues at all sharpening it on SPS-II stones . Actually for that matter I don't have an issue using my King 1000 on my knives in CPM-M4, ZDP-189, and HAP40 either actually.

 

[Steel_Drake]

With M4 or Hap40, sharpen 15dps to dry-shave using SPSII vs DMT EF. Slice phonebook paper 10 times, whittle some pine. Which one has higher keenness (thinner apex radius)?

Luong,

I would always expect an apex produced edge-leading passes on a non-friable abrasive like a DMT EF to have a higher keenness than an apex set using edge-leading passes on a friable abrasive with a slurry such as an SPS-II or King waterstone since making edge leading passes on a friable stone with a slurry necessarily will involve some rounding over of the apex as it plows into abrasive particles in the slurry above the surface of the stone.

As a result, I would expect a higher keenness on the apex set on the DMT EF even if the knife in question was 1095. Personally, I prefer to use highly friable abrasives to shape the edge bevel and then create a micro-bevel to set the apex using a non-friable abrasive (e.g. diamond plate, solid sintered ceramic rod, edge-trailing strokes on a coarse particulate abrasive strop, etc.).

Nonetheless, here is a video I made previously showing me sharpening a blade in CPM-M4 to the point where it will cleanly slice and push-cut newsprint with the grain on a King 1000:

[video=youtube;wH9f1BDIvu0]http://www.youtube.com/watch?v=wH9f1BDIvu0[/video]

And here is a video of me using an SPS-II 1000 and a coarse particulate abrasive strop (30 micron CBN on suede) to go from cutting off the previous apex to doing crossgrain pushcuts on newsprint in 5 minutes on a blade in HAP40:

[video=youtube;LB-sm7M0d_I]http://www.youtube.com/watch?v=LB-sm7M0d_I[/video]

I will post a video of my results with the Maxamet mule once I've received it, which will be a while since it will be international shipping.

 

[BluntCut MetalWorks]

Nice steady sharpening strokes with high keenness edges :thumbup:

'Whittle some pine' is about testing apex durability, in this case at high keenness before settle down with a working sharpness. If going further to 'whittle some bone', again which one end up with thinner apex radius (consider this is - more dull - working sharpness)?

From a theoretical view - if a blade made from one large VC, in which way would SPSII/King stone sharpens (100% shaping VC) this blade? Deductive to 10V apex consists over 25% of VC(in volume spatial perspective) or other PM steel with 2-5um micron dia VC at any non-zero% carbide volume.

In practice & perhaps common knowledge - users of extra high wear resistant steels readily accept working-edge, relegate sub-micron edge as lousy ROI of time/effort. I disagree with the latter part, because using appropriate abrasive (diamond/cbn), these steels will support working edge at higher keenness.

Luong,

I would always expect an apex produced edge-leading passes on a non-friable abrasive like a DMT EF to have a higher keenness than an apex set using edge-leading passes on a friable abrasive with a slurry such as an SPS-II or King waterstone since making edge leading passes on a friable stone with a slurry necessarily will involve some rounding over of the apex as it plows into abrasive particles in the slurry above the surface of the stone.

As a result, I would expect a higher keenness on the apex set on the DMT EF even if the knife in question was 1095. Personally, I prefer to use highly friable abrasives to shape the edge bevel and then create a micro-bevel to set the apex using a non-friable abrasive (e.g. diamond plate, solid sintered ceramic rod, edge-trailing strokes on a coarse particulate abrasive strop, etc.).

Nonetheless, here is a video I made previously showing me sharpening a blade in CPM-M4 to the point where it will cleanly slice and push-cut newsprint with the grain on a King 1000:
..
And here is a video of me using an SPS-II 1000 and a coarse particulate abrasive strop (30 micron CBN on suede) to go from cutting off the previous apex to doing crossgrain pushcuts on newsprint in 5 minutes on a blade in HAP40:
..
I will post a video of my results with the Maxamet mule once I've received it, which will be a while since it will be international shipping.

 

[Steel_Drake]

Nice steady sharpening strokes with high keenness edges :thumbup:

Thanks. I've spent a lot of time trying to figure out the fastest approach to achieve an apex with a very high level of push cutting sharpness without sacrificing too much slicing aggression.

'Whittle some pine' is about testing apex durability, in this case at high keenness before settle down with a working sharpness. If going further to 'whittle some bone', again which one end up with thinner apex radius (consider this is - more dull - working sharpness)?

Ah, I didn't understand you clearly. How much pine whittling should be necessary to check for the strength of the apex? Would making some shavings from a length of pine be good enough to test this?

From a theoretical view - if a blade made from one large VC, in which way would SPSII/King stone sharpens (100% shaping VC) this blade? Deductive to 10V apex consists over 25% of VC(in volume spatial perspective) or other PM steel with 2-5um micron dia VC at any non-zero% carbide volume.

My expectation would be that the SPS-II would cut solid VC, but that is just an assumption on my part based on it working reasonably well on the ceramic knife I sharpened on it. I will have to wait until I have something in Maxamet to see what will happen in reality though.

In practice & perhaps common knowledge - users of extra high wear resistant steels readily accept working-edge, relegate sub-micron edge as lousy ROI of time/effort. I disagree with the latter part, because using appropriate abrasive (diamond/cbn), these steels will support working edge at higher keenness.

My usage is mostly food prep, cardboard, and clam-shell packaging and in these applications I'm much more interested in the ability of the micro-bevel to resist any microscopic chipping than any other property as, so long as the micro-bevel doesn't microscopically chip, I can easily keep touching up the microbevel back to near initial sharpness for some time. This use pattern is why I don't already have any ultra-high carbide volume steels really. Even with ZDP-189 I find it has a little too much of a tendency to wear by microscopically chipping.

 

[BluntCut MetalWorks]

There is a large gap in hardness between SiC and VC. Ceramic blade: Zirconia (https://en.wikipedia.org/wiki/Zirconium_dioxide) is way softer. When dealing with a solid block of it, it seems harder because harder for the abrasive to penetrate.

https://www.tedpella.com/Material-Sciences_html/Abrasive_Grit_Grading_Systems.htm

Just shave & with slight carving out motion into pine - do this for 5-10 times. Try harder wood if pine fail to delineate the differences.

edit to add: zdp189 has high carbide volume but mostly in form of CrxCy (Chromium Carbide). CrC is much softer than SiC

 

[DeadboxHero]

Steel_Drake - thanks for posted the video: sigma power select II sharpens a ceramic knife. You made good points along with unfounded/untested claim on that stone can effectively abrade any steels regardless of carbide volume. VC is harder than SiC and AO ceramic. When SiC abrasive is small enough, excavate/plow component of sharpening is drastically reduce against steels with high VC volume. I indirectly mentioned in my previous posts about SiC belts are ineffective against 10V when SiC grit size higher than 320. Actually SiC belts 120-220 dies really fast against 10V too because SiC is highly friable, so after a few revolutions, an almost pure thick (think, multi-thin layers if you will) SiC layer totally glass smooth. Sure, stone will release more abrasive but when abrasive is much softer than target(vc), well can't shape those target!

Russ/mycough spoke from quite a bit experience with sharpening high alloy, especially high carbide volume steels. We are here to learn from each-other, no one try to one-up. The more you learn & know, the less you know & much more need to learn - speaking for myself, I reckon!

Bluntcut,

I'm aware that VC is harder than SiC, however I was under the impression that a highly friable SiC benchstone should expose fresh abrasive quickly enough in use to continue cutting effectively, without the problem of quickly wearing out like SiC belts appear to.

Also, I'm not sure if I'm understanding you correctly, but to clarify, are you saying that a steel with a high vanadium carbide volume such as 10V is harder to grind than a ceramic knife? If so, would you happen to know any reasonably priced commercially available knives made with a steel with a high enough carbide volume that I could buy one and try sharpening it on my SiC waterstones? Would a Spyderco Manix LW in s110v have enough vanadium to test this? Or would I need a knife in 10V specifically?

Worst case scenario, assuming your prices are reasonable, I'd be willing to buy one of your customs in 10V just for the purpose of testing out which of my sharpening stones can successfully sharpen it in a reasonable time frame, and to make a video of the results. I've often found that with sharpening knowledge there is no alternative for simply trying something yourself to see what will happen.

Bravo for being mature and civil guys! Good stuff

 

[DeadboxHero]

Steel Drake,

I like the idea of the sigma stones, super charged Norton crystolon stones with more finishing options.

Could you give me a run down of the how the different grits behave? Feedback, speed, mud, dish, etc

Thanks man.

 

[Father & Son Traditional Sharpening]

I would not classify the Crystolon anywhere near the SPSII stones in characteristics, excepting maybe the type of abrasive between the two (SiC). The SPS II have virtually no binder, which allows the abrasive to be released *trivially*… whereas the Crystolon is more or less an extremely hard bonded stone similar to glass fusing the abrasives together. The main difference would be that the Crystolon will give up the goat somewhere near S30V and up as far as the ability to keep cutting is concerned (glazing) whereas the SPSII should just keep chugging along for any of the common high carbide volume steel/processing.