5:08 For anyone who says this, Science of Sharp has an article titled "Carbides in K390" where he shows a stone that's a mixture of AlOx and SiC cleanly abrading both the steel matrix and carbides in K390. SiC cuts VC, their hardness ranges roughly overlap, with VC only *on average* being harder. SEM imagery is surely sufficient evidence in favor of silicon carbide abrasives. He has other images showing AlOx stones merely abrading the steel matrix and exposing the carbides. SiC, CBN, and Diamond are sufficient for high alloy. AlOx is probably best left for more standard alloys.
Cliff stamp always told me, if a stone is fairly friable, chances are itll cut whatever steel i have. I generally used that rule of thumb and tested things for myself. Even if there are carbides tearout and such, it is such a miniscule thing, in everyday cutting, nonone will know. I believe only the most discerning edge tester would possibly see a difference 🤷♂️
@Jef I really want Cedric & Ada to do a test on exactly this. Take something like 15v or Maxamet and do a sharpening with diamond abrasives and an equivalent sharpening (same angle, grit etc) with an aluminum oxide stone. Test final sharpness and edge longevity. We know what can abrade what, but whether or not it makes much practical difference is yet to be investigated.... Someday I want to buy a Shapton Glass 500 just to mess around with this idea.
@@Aerzon1v1 that would be a video i too would like to see. Those tests are interesting, and it gives a general idea, but there are so many factors at play. pressure, speed, and of course, what the edge is cutting into after the rope. In his case, what is it? Wood? Hitting angles and hard material, can damage the apex, just as much as abrasion. Again, good rule of thumb, but I take it all with a grain of salt. It is the reason I never started doing cut tests. Just too many variables that can skew the results. Bess 'C' is bad enough lol.
To further this point, I’ve sharpened k390 on the Gritomatic SiC stones and venevs… If anything, the edges off the SiC stones have lasted longer because I enjoy sharpening on them so much. To each their own. If someone is worried about carbide tear out, use diamond. Personally, I’ll use the SiC stones on anything. I could be mistaken, but I think larin Thomas said it was only a concern at all on high grit edges. If that’s the case, seems like in the cases it presents itself, you’re not really worried about edge retention anyway?
Watching you sharpen REX 121 reminded me of sharpening the Sandrin Torino (Tungsten Carbide). I am on the fence on this knife because of the micro chips and the effort to sharpen it. I would put the 15 degree angle back on the knife and leave it with a 1200 grit finish. Great video! I really appreciate the amount of effort that went into making it. Thanks again.
Yeah, that Sandrin is a beast to sharpen. Glad you enjoyed the video! I had a buddy loan me his to dink with. I never found anything reliable to cut it well, other than spyderco ceramics.
As always, amazing work. Thanks, man! Much appreciated. The next time I have a few hours I’ll probably add the notch. Lol. I hate sharpening the heels of Spyderco knives. 😂
I tend to use those diamond files you can get cheaply at harbor freight. They come with many different shapes. Under $15. We were just discussing trying to place one in a mill, to keep it powered and stationary
@@Jefah I see. Yes I used the same diamond HF file when I added a choil to my Cruwear Military Makes a hell of a difference when sharpening. You know all too well
Thanks Jef. I always enjoy your videos. Yours, Jerad’s (Neeves Knives) and Alex’s (Outdoors55) are my favorites. Man those Nano hone stones seem soft. A Venev wouldn’t have done that; it would have worn out along the edge but not slice like that. I think that’s why Jerad prefers to use the Atoma 140 for reprofiling or fixing chips and then switches to bonded diamond stones afterwards. I went ahead and got an Atoma 140 for that reason.
This knife will absolutely take bites out of venevs. 100% it did. Exact same situation just left hand pull stroke. Albeit smaller chips came out, but it definitely bite my venev 400. The nano hones do seem much softer, but the venevs aren’t impervious to damage from Rex 121.
Damn! I have no experience with super wear resistance steels like Rex121, Maxamet and 15V, but it sounds like it’s best to stick to diamond plates, especially with the course and medium grits, or if using resin bonded diamond stones, be careful with the strokes.
Interestingly, Jerad made a short recently on Rex121 and he used atomas 140, 400 and stopped at 600, then minimized the burr with venev 7/5 micron. He stopped at 600 which tells me he believes Rex121 is better with a toothy edge. ruclips.net/user/shortsEX49CmKkhno?si=mCYnyZv1930eDRwT
I find i get better results with sic and finishing on diamond, or just stopping at the 2500 sic stone. Everyone has thier own preference. Neeves does much more sharpening on these type of steels than i do. Ill still stick with what works for me. I encourage everyone to try things for themselves. You never know. You may find you prefer coarse 120 grit edges over polished. Or vice vers. Gotta find what you like and run with it 👍
I notice you do most of your videos on hard steel knives for folders. Do you have any plans to do hard chef knife steels (hap40, zdp189, etc)? love this format/comparison.
@@biscuitkitchentreviews I’ve only a handful of decent kitchen knives. None in super steels. W-2 and bd1, is about as modern as any i own. It’s not that i dislike them, im just not a chef. They would be wasted on me. However, i do use pocket knives, on the daily. Especially at work. Hence my videos, always showcasing them. As for the few kitchen knives i own, I’ve got videos up. Think my japanese knives are either in aogami, or blue paper? I forget which 🤷♂️ there’s multiple videos on my channel. Just search my channel for gyoto or bunka. They should pop up. The rest you can probably find searching kitchen knives. All that said, i have sharpened and own several spydercos in zdp189. I highly rank that stuff. It’s up there in my top 3 favorite steels. Hap40 i did one video on with a spyderco, if memory serves. Super gold 2 on a delica. Im sure there are several others. Spyderco is one of the only companies making these steels in pocket knives, after all; so they have a bit of a monopoly, on my videos for them 😁
Curious what the Latte and Arashiyama would do. I have this knife and those stones, but don't feel the need to dull a perfectly new and sharp Rex 121. BTW, thanks for recommending those two stones, they are most excellent.
@@Jef I didn't know the Imanishi Arashiyama #1000 was the same as the green brick of joy. Thanks for the heads up. Edit: Unless your calling the Arashiyama #1000 a "green brick."
@@PeteyMcSavage they both cut it no prob. Well the mutt did. I didnt test the manticore but its so doggon coarse itll cut time and space. Rex121 wouldn’t stand a chance
Sic stones are my favorite your right forums are interesting but also full of bad info sic will cut any steel. For me around 400 grit cut Rex 121 very cleanly with good pressure
@@PeteyMcSavage it’s not just forums, but they are easy to pick on. I often get them in my comments as well. Ive never ran into a steel that the gritomatic soc stones couldnt sharpen. I tend to get better results with them. Diamonds and i just never see eye to eye.
Nice job, Jef. Those nano hones seem like real garbage. They never interested me due to the guy behind them but I won’t get into that here. You’re doing a good service to sharpeners by showing their low quality. On the Spyderco bevel/ricasso junction (unsharpend bevel portion) I grind it on Atoma 140/400 so it becomes a part of the bevel as the Atomas really reach into the corner and allow you to sharpen it right up to the 90° ricasso. After about two sharpenings it’s completely gone. With the way they’ve done it on the Native Chief, and also the way they’ve done the plunge line (~45° rather than 90°) I may actually have to add a small choil on that one right in the ~45° plunge line as it’s annoying and catches more than a very small choil would. Other than that it’s a brilliant blade. On Rex121, I don’t like it. I like the HRC…I love high HRC (65-70), just not the steel as it can’t hold _high_ sharpness too long. I suppose it will depend on what each persons definition of sharp is as to whether they like it or not. It cuts various materials for a long time, sure; but at a much lower level of sharpness to what I find acceptable and thus useful. Maxamet is a bit better in this regard but still far from ideal. When you don’t let your knives go dull (also open to interpretation) what point do high carbide steel have in cutlery? I just don’t see the claimed performance in them. If you remember, Cliff proved years ago - and long before Maxamet & Rex121 were in the hands of anyone - that such steels max out giving _any_ performance benefit at S30V level. Also of interest is on the manufacturers data sheets for these high carbide steels under “intended uses,” nowhere is “cutlery” listed. 😂 Edit: it was also Cliff that actually recommended Maxamet and Rex121 as extreme steels (not ideal steels) to Sal on the Spyderco forum years ago
Nice write up. I do rem cliff and his experiments showing how simple geometry changes would out perform super steels, using things like 440a or 420hc. Amazing man. Serious loss to the world, since he passed. Those sharpening notches arent for everyone. Of course ive had mine get snagged while cutting, but i find it negligible, in the over all scheme. Everyone has thier own pref. As for high sharpness, i can not say, on this stuff. I havent personally put it to work. My buddy said he has broken down over 400 boxes, and the edge remained nice. Now that could be in part due to the geometry, but when i received it, areas still felt sticky sharp. It was one of the reasons i pointed out how my edge had that polished slickness to it. The stickiness just wasnt there like i received it. What contributed to that? Im not sure. Will have to inquire if he stropped it or touched it up on anything.
@@Jef He was. With the sticky vs slick apex- the grits, medium used, pressure, and direction of pass is why; the higher you go, generally, the less sticky. The worst offenders are leather strops with compounds. Hard pieces of wood with Diamond (5-10μ) are better at retaining aggression (stick) as it has no compression. A good way to achieve high sharpness and still retain a lot of aggression (stick) is straight off of a stone and then use grit minimization techniques to refine it. Also, going back down a few grits from the highest/last grit with ultra light passes can get that sticky apex back while simultaneously retaining most of the highly refined apex from the super high grit…it will still whittle free hanging hair multiple times. Going back to a stone for a few light passes on the micro _after_ stropping will also achieve it. So, if you finish on 30k and find it’s not sticky, go back to a 3-8k stone and micro it _very_ lightly, often with less weight than the knife itself; alternate edge leading passes, ricasso to tip for standard draw cuts, or tip to ricasso for thrust cuts. These are little things I’ve learned from Cliff over the years, tried them, and then adopted them as they produce good results. Each steel and abrasive requires testing to work out what works best together. Many things seem counterintuitive but the results speak for themselves.
@@Wolf_K yep that’s pretty much what i told the owner. If he wants that sticky feeling he can just go to a lower grit and Micro bevel it. Shouldnt be hard at all. Few passes at 15°+ and he’s gold 👌 I always screw micros up. However this would be a perfect candidate for the sharp maker. I can produce em with that 👍
@@Aa-ron22 some folk just like the high performance low angles give them. It all is dependent on what you’re cutting, i suppose. i do agree about the pocket knife angle. I like 18°. For me it’s the perfect blend of acuteness, coupled with stability. I don’t know how i ended up with that being my natural hand position, for most edges. It always comes out that way, when i measure them on my goniometer.
@Jef that'd be sweet 😋 the debado ld21 is a lot of people's #1 coarse stone. That, sp120, norton crystolon. The grit sic compared to that would make for a cool comparison!
Nice little experiment you got going there! A coarse friable alu oxide stone will work surprisingly well on the higher alloyed steels, I remember Cliff using a Naniwa Super stone 400 with success. For finishing those steels, a freshly dressed resin bonded seems to work really well. Basically what you’ve done here as well.
I didn’t get around to testing all i wanted. The king 1-1200 would have been nice but i totally forgot. Also the suehiro g-8 8k. It’s sic so technically should work. So many choices. I’ll prob break down and buy one just to sharpen and test
5:08
For anyone who says this, Science of Sharp has an article titled "Carbides in K390" where he shows a stone that's a mixture of AlOx and SiC cleanly abrading both the steel matrix and carbides in K390. SiC cuts VC, their hardness ranges roughly overlap, with VC only *on average* being harder. SEM imagery is surely sufficient evidence in favor of silicon carbide abrasives. He has other images showing AlOx stones merely abrading the steel matrix and exposing the carbides.
SiC, CBN, and Diamond are sufficient for high alloy. AlOx is probably best left for more standard alloys.
Cliff stamp always told me, if a stone is fairly friable, chances are itll cut whatever steel i have. I generally used that rule of thumb and tested things for myself. Even if there are carbides tearout and such, it is such a miniscule thing, in everyday cutting, nonone will know. I believe only the most discerning edge tester would possibly see a difference 🤷♂️
@Jef I really want Cedric & Ada to do a test on exactly this. Take something like 15v or Maxamet and do a sharpening with diamond abrasives and an equivalent sharpening (same angle, grit etc) with an aluminum oxide stone. Test final sharpness and edge longevity.
We know what can abrade what, but whether or not it makes much practical difference is yet to be investigated....
Someday I want to buy a Shapton Glass 500 just to mess around with this idea.
@@Aerzon1v1 that would be a video i too would like to see. Those tests are interesting, and it gives a general idea, but there are so many factors at play. pressure, speed, and of course, what the edge is cutting into after the rope. In his case, what is it? Wood? Hitting angles and hard material, can damage the apex, just as much as abrasion. Again, good rule of thumb, but I take it all with a grain of salt. It is the reason I never started doing cut tests. Just too many variables that can skew the results. Bess 'C' is bad enough lol.
Thanks for this info!
To further this point, I’ve sharpened k390 on the Gritomatic SiC stones and venevs… If anything, the edges off the SiC stones have lasted longer because I enjoy sharpening on them so much. To each their own. If someone is worried about carbide tear out, use diamond. Personally, I’ll use the SiC stones on anything. I could be mistaken, but I think larin Thomas said it was only a concern at all on high grit edges. If that’s the case, seems like in the cases it presents itself, you’re not really worried about edge retention anyway?
Watching you sharpen REX 121 reminded me of sharpening the Sandrin Torino (Tungsten Carbide).
I am on the fence on this knife because of the micro chips and the effort to sharpen it.
I would put the 15 degree angle back on the knife and leave it with a 1200 grit finish.
Great video! I really appreciate the amount of effort that went into making it. Thanks again.
Yeah, that Sandrin is a beast to sharpen. Glad you enjoyed the video! I had a buddy loan me his to dink with. I never found anything reliable to cut it well, other than spyderco ceramics.
As always, amazing work. Thanks, man! Much appreciated. The next time I have a few hours I’ll probably add the notch. Lol. I hate sharpening the heels of Spyderco knives. 😂
Meeeee too 😂
Rat tail file makes quick work of adding them
I tend to use those diamond files you can get cheaply at harbor freight. They come with many different shapes. Under $15. We were just discussing trying to place one in a mill, to keep it powered and stationary
@@Jefah I see.
Yes I used the same diamond HF file when I added a choil to my Cruwear Military
Makes a hell of a difference when sharpening. You know all too well
Good video very interesting
Thanks, I hope you enjoyed it!
Thanks Jef. I always enjoy your videos. Yours, Jerad’s (Neeves Knives) and Alex’s (Outdoors55) are my favorites.
Man those Nano hone stones seem soft. A Venev wouldn’t have done that; it would have worn out along the edge but not slice like that.
I think that’s why Jerad prefers to use the Atoma 140 for reprofiling or fixing chips and then switches to bonded diamond stones afterwards. I went ahead and got an Atoma 140 for that reason.
Thank you for the kind words and placing me next to good company 😁
The 140 atoma is a beast. Its fantastic for super wear resistant stuff.
This knife will absolutely take bites out of venevs. 100% it did. Exact same situation just left hand pull stroke. Albeit smaller chips came out, but it definitely bite my venev 400. The nano hones do seem much softer, but the venevs aren’t impervious to damage from Rex 121.
Damn! I have no experience with super wear resistance steels like Rex121, Maxamet and 15V, but it sounds like it’s best to stick to diamond plates, especially with the course and medium grits, or if using resin bonded diamond stones, be careful with the strokes.
Interestingly, Jerad made a short recently on Rex121 and he used atomas 140, 400 and stopped at 600, then minimized the burr with venev 7/5 micron. He stopped at 600 which tells me he believes Rex121 is better with a toothy edge.
ruclips.net/user/shortsEX49CmKkhno?si=mCYnyZv1930eDRwT
I find i get better results with sic and finishing on diamond, or just stopping at the 2500 sic stone. Everyone has thier own preference. Neeves does much more sharpening on these type of steels than i do. Ill still stick with what works for me. I encourage everyone to try things for themselves. You never know. You may find you prefer coarse 120 grit edges over polished. Or vice vers. Gotta find what you like and run with it 👍
I notice you do most of your videos on hard steel knives for folders. Do you have any plans to do hard chef knife steels (hap40, zdp189, etc)? love this format/comparison.
@@biscuitkitchentreviews I’ve only a handful of decent kitchen knives. None in super steels. W-2 and bd1, is about as modern as any i own. It’s not that i dislike them, im just not a chef. They would be wasted on me. However, i do use pocket knives, on the daily. Especially at work. Hence my videos, always showcasing them. As for the few kitchen knives i own, I’ve got videos up. Think my japanese knives are either in aogami, or blue paper? I forget which 🤷♂️ there’s multiple videos on my channel. Just search my channel for gyoto or bunka. They should pop up. The rest you can probably find searching kitchen knives.
All that said, i have sharpened and own several spydercos in zdp189. I highly rank that stuff. It’s up there in my top 3 favorite steels. Hap40 i did one video on with a spyderco, if memory serves. Super gold 2 on a delica. Im sure there are several others. Spyderco is one of the only companies making these steels in pocket knives, after all; so they have a bit of a monopoly, on my videos for them 😁
Curious what the Latte and Arashiyama would do. I have this knife and those stones,
but don't feel the need to dull a perfectly new and sharp Rex 121. BTW, thanks for
recommending those two stones, they are most excellent.
Duno about the latte but the green brick wont cut it. It wouldnt cut steels like s30v. So rex121 would eat right thru it 😁
@@Jef I didn't know the Imanishi Arashiyama #1000 was the same
as the green brick of joy. Thanks
for the heads up.
Edit: Unless your calling the Arashiyama #1000
a "green brick."
@@JohnDoe-zb7dz oh damn i got those mixed up. The 1k I’m unsure of. I’ve never used that one. I was thinking of the green brick 🤦♂️ sorry
@@Jef That's okay. I figured one of us was mixed up. Thanks Jef!
Yea 9 times outta 10 itll be me 😂
I was hoping to see the manticore and mutt
@@PeteyMcSavage they both cut it no prob. Well the mutt did. I didnt test the manticore but its so doggon coarse itll cut time and space. Rex121 wouldn’t stand a chance
Sic stones are my favorite your right forums are interesting but also full of bad info sic will cut any steel. For me around 400 grit cut Rex 121 very cleanly with good pressure
@@PeteyMcSavage it’s not just forums, but they are easy to pick on. I often get them in my comments as well. Ive never ran into a steel that the gritomatic soc stones couldnt sharpen. I tend to get better results with them. Diamonds and i just never see eye to eye.
Nice job, Jef.
Those nano hones seem like real garbage. They never interested me due to the guy behind them but I won’t get into that here. You’re doing a good service to sharpeners by showing their low quality.
On the Spyderco bevel/ricasso junction (unsharpend bevel portion) I grind it on Atoma 140/400 so it becomes a part of the bevel as the Atomas really reach into the corner and allow you to sharpen it right up to the 90° ricasso. After about two sharpenings it’s completely gone.
With the way they’ve done it on the Native Chief, and also the way they’ve done the plunge line (~45° rather than 90°) I may actually have to add a small choil on that one right in the ~45° plunge line as it’s annoying and catches more than a very small choil would. Other than that it’s a brilliant blade.
On Rex121, I don’t like it. I like the HRC…I love high HRC (65-70), just not the steel as it can’t hold _high_ sharpness too long. I suppose it will depend on what each persons definition of sharp is as to whether they like it or not. It cuts various materials for a long time, sure; but at a much lower level of sharpness to what I find acceptable and thus useful. Maxamet is a bit better in this regard but still far from ideal.
When you don’t let your knives go dull (also open to interpretation) what point do high carbide steel have in cutlery? I just don’t see the claimed performance in them.
If you remember, Cliff proved years ago - and long before Maxamet & Rex121 were in the hands of anyone - that such steels max out giving _any_ performance benefit at S30V level.
Also of interest is on the manufacturers data sheets for these high carbide steels under “intended uses,” nowhere is “cutlery” listed. 😂
Edit: it was also Cliff that actually recommended Maxamet and Rex121 as extreme steels (not ideal steels) to Sal on the Spyderco forum years ago
Nice write up. I do rem cliff and his experiments showing how simple geometry changes would out perform super steels, using things like 440a or 420hc. Amazing man. Serious loss to the world, since he passed.
Those sharpening notches arent for everyone. Of course ive had mine get snagged while cutting, but i find it negligible, in the over all scheme. Everyone has thier own pref. As for high sharpness, i can not say, on this stuff. I havent personally put it to work. My buddy said he has broken down over 400 boxes, and the edge remained nice. Now that could be in part due to the geometry, but when i received it, areas still felt sticky sharp. It was one of the reasons i pointed out how my edge had that polished slickness to it. The stickiness just wasnt there like i received it. What contributed to that? Im not sure. Will have to inquire if he stropped it or touched it up on anything.
@@Jef
He was.
With the sticky vs slick apex- the grits, medium used, pressure, and direction of pass is why; the higher you go, generally, the less sticky. The worst offenders are leather strops with compounds. Hard pieces of wood with Diamond (5-10μ) are better at retaining aggression (stick) as it has no compression.
A good way to achieve high sharpness and still retain a lot of aggression (stick) is straight off of a stone and then use grit minimization techniques to refine it.
Also, going back down a few grits from the highest/last grit with ultra light passes can get that sticky apex back while simultaneously retaining most of the highly refined apex from the super high grit…it will still whittle free hanging hair multiple times. Going back to a stone for a few light passes on the micro _after_ stropping will also achieve it.
So, if you finish on 30k and find it’s not sticky, go back to a 3-8k stone and micro it _very_ lightly, often with less weight than the knife itself; alternate edge leading passes, ricasso to tip for standard draw cuts, or tip to ricasso for thrust cuts.
These are little things I’ve learned from Cliff over the years, tried them, and then adopted them as they produce good results. Each steel and abrasive requires testing to work out what works best together.
Many things seem counterintuitive but the results speak for themselves.
@@Wolf_K yep that’s pretty much what i told the owner. If he wants that sticky feeling he can just go to a lower grit and Micro bevel it. Shouldnt be hard at all. Few passes at 15°+ and he’s gold 👌
I always screw micros up. However this would be a perfect candidate for the sharp maker. I can produce em with that 👍
Excellent comment.
Man I’ll never understand why people make an angle below 17 on a pocket knife. And wonder why it chips 18 is the perfect number
@@Aa-ron22 some folk just like the high performance low angles give them. It all is dependent on what you’re cutting, i suppose. i do agree about the pocket knife angle. I like 18°. For me it’s the perfect blend of acuteness, coupled with stability. I don’t know how i ended up with that being my natural hand position, for most edges. It always comes out that way, when i measure them on my goniometer.
@ the middle of my thumb as a guide is 18 lol I think a lot of people is the same
@ nice 👍 works out perfectly
👻
Debado ld21 vs grit sic 240?
Doable but i dinked mine up with that cashew laquer. If youre curious i can slap something together and see how it pans out
@Jef that'd be sweet 😋 the debado ld21 is a lot of people's #1 coarse stone. That, sp120, norton crystolon. The grit sic compared to that would make for a cool comparison!
Oof shes a tough sob.
@@adanma17 very 💪
Nice little experiment you got going there! A coarse friable alu oxide stone will work surprisingly well on the higher alloyed steels, I remember Cliff using a Naniwa Super stone 400 with success. For finishing those steels, a freshly dressed resin bonded seems to work really well. Basically what you’ve done here as well.
I didn’t get around to testing all i wanted. The king 1-1200 would have been nice but i totally forgot. Also the suehiro g-8 8k. It’s sic so technically should work. So many choices. I’ll prob break down and buy one just to sharpen and test
Couldn’t blame you! Looking forward to the results
@@lars43771
Yep, along with that Chosera 400 he also used a Suehiro 700 extensively.