Diamond stones

CKTG has a large amount of Edge Pro products so we've dedicated a forum to questions on Edge Pro sharpening systems, accessories and techniques.
Drafter
Posts: 17
Joined: Tue Sep 26, 2017 2:08 pm
Been thanked: 2 times

Diamond stones

Post by Drafter »

When will CKTG get a 2000 grit diamond stone
User avatar
ChefKnivesToGo
Site Admin
Posts: 16857
Joined: Tue Jan 24, 2017 2:23 pm
Location: Madison, WI
Has thanked: 2051 times
Been thanked: 3275 times
Contact:

Re: Diamond stones

Post by ChefKnivesToGo »

I’m going to ask about this on my next order. Not sure if they do them but if they do, I’ll get them.
Image
Mark Richmond
Co-Owner Chefknivestogo
https://www.chefknivestogo.com/newarrivals.html
User avatar
Drewski
Posts: 1309
Joined: Wed Mar 28, 2018 2:01 am
Location: Manitoba, Canada
Has thanked: 429 times
Been thanked: 46 times

Re: Diamond stones

Post by Drewski »

What situations call for a higher grit diamond stone? I've got a 140 that I use to flatten stones or when I've got a big chip to remove. Seems like there's been more talk lately about diamond stones that are medium and higher grit, and I feel like I'm in the dark with my lack of knowledge.
User avatar
Otaku19
Posts: 299
Joined: Fri Jan 27, 2017 5:43 pm
Has thanked: 1 time
Been thanked: 1 time

Re: Diamond stones

Post by Otaku19 »

High carbide steels are more abrasion resistant and most of the waterstones on the market won't properly cut the carbides. I've even read about carbides being torn out by alumina based stones, though this seems to be controversial in the sharpening world. Silicone carbide and diamonds are the most effective way to cut the higher carbide steels. I've had great success in using the Spyderco ceramic stones which are still alumina based and I've never experienced any carbides being ripped from the edge.
User avatar
lsboogy
Posts: 1486
Joined: Tue Jun 05, 2018 1:23 pm
Location: Minneapolis
Has thanked: 41 times
Been thanked: 132 times

Re: Diamond stones

Post by lsboogy »

I'll take my J Nats to any steel - hardest steel I have seen was about 73HRC - machine tools for cutting exotic materials. The machinists sharpened the tools with whetstones.
User avatar
Organic
Posts: 131
Joined: Thu Aug 10, 2017 11:51 am
Location: Charlton, MA, USA
Has thanked: 2 times

Re: Diamond stones

Post by Organic »

lsboogy wrote: Mon Feb 04, 2019 9:33 pm I'll take my J Nats to any steel - hardest steel I have seen was about 73HRC - machine tools for cutting exotic materials. The machinists sharpened the tools with whetstones.
Wow, that's some hard steel!
lenny
Posts: 1
Joined: Sun Feb 24, 2019 10:00 pm

Re: Diamond stones

Post by lenny »

Otaku19 wrote: Mon Feb 04, 2019 5:15 am High carbide steels are more abrasion resistant and most of the waterstones on the market won't properly cut the carbides. I've even read about carbides being torn out by alumina based stones, though this seems to be controversial in the sharpening world. Silicone carbide and diamonds are the most effective way to cut the higher carbide steels. I've had great success in using the Spyderco ceramic stones which are still alumina based and I've never experienced any carbides being ripped from the edge.
I've heard about this so called tearing as well; Ben Dale mentioned something like this happening with carbides on modern, ridged honing steels in a recent interview. I'm inclined to believe it may be an issue too. However even if we assume this is something that we should worry about, after the 140 grit diamond stone sets the bevel and cleaves the carbides shouldn't we be fine?
User avatar
lsboogy
Posts: 1486
Joined: Tue Jun 05, 2018 1:23 pm
Location: Minneapolis
Has thanked: 41 times
Been thanked: 132 times

Re: Diamond stones

Post by lsboogy »

I'd guess the machinists in my plant would agree differently Lenny, they sharpen tools with better carbide structure and much harder steel than the knives we see here same as they have been doing for years. You can't machine flight control surfaces with dull tools - most nickel alloys work harden far beyond steel, so any plastic deformation of the material will result in scrap parts (big money for some - and the gear materials used in the geared turbo fan motors are very precise). But the bigger bits for some of the machining centers cost far more than our knives, and they do use stones and magnifiers to do the final edge work. Lotsa voodoo out there - well made steel has carbides that are bound far more tightly than you would believe, especially Martensitic steels. Austentite is face centered cubic, so if you get something that can apply a heck of a lot of pressure, you MIGHT get a chance at pulling a carbon out - Martensite is body centered tetragonal, so no chance you could pull out a carbide.
Wjhunt
Posts: 302
Joined: Sun Apr 08, 2018 12:36 pm
Has thanked: 15 times
Been thanked: 44 times

Re: Diamond stones

Post by Wjhunt »

Seems like there’s a description of rocks in jello that was used to describe steel with a high percentage of vanadium. The hrc of the steel has nothing to do with it. Abrasion resistance is the problem. It’s not a big deal until the sharpening particles become smaller than the carbides. I have not been interested in PM steels for a while so I can’t remember what the actual grit of the stone is when you have to worry about it. Seems like it’s over 2k but that’s a guess.
User avatar
lsboogy
Posts: 1486
Joined: Tue Jun 05, 2018 1:23 pm
Location: Minneapolis
Has thanked: 41 times
Been thanked: 132 times

Re: Diamond stones

Post by lsboogy »

Most fcc/bcc carbides are on the order of 50nm and will be significantly smaller than a whetstone grain. They are bound with something like -55ev/atom (cohesive force) and cannot be separated by human induced force. If they are properly dissolved in alloy steel, it would take an act of God to remove them. Carbon will precipitate
First stage, excess carbon segregates into defects. Second stage, cementite forms or iron carbides form (in high carbon alloys), third (final stage) leads to crystallization of ferrite plates and equiaxed grains.
If you knife heat treat only gets to first stage, you will have big clumps (3-400nm or larger) of carbon in the steel - you might be able to get those out with a stone. Anything else and it will be impossible to remove carbide in white steel with your hands
Wjhunt
Posts: 302
Joined: Sun Apr 08, 2018 12:36 pm
Has thanked: 15 times
Been thanked: 44 times

Re: Diamond stones

Post by Wjhunt »

https://knifesteelnerds.com/2018/08/27/ ... stability/
I prefer carbon (especially blue #2) for a gyuto but I do like S30v for a folder. For the folders I use a 400 grit stone and strop with 1 micron diamond. You would need access to a SEM to prove carbide pullout and I’m just not that concerned about it.
User avatar
lsboogy
Posts: 1486
Joined: Tue Jun 05, 2018 1:23 pm
Location: Minneapolis
Has thanked: 41 times
Been thanked: 132 times

Re: Diamond stones

Post by lsboogy »

http://www.phase-trans.msm.cam.ac.uk/20 ... nsite.html

food for thought - shows why only defects (big hinks of carbon) could be stripped. Properly done steel will have the carbon diffused (dissolved) into the lattice structure of the steel -

if you look towards the bottom of the doc, you can start to see some of the particles at the 50nm level - how well your steel is cooked is a function of heat treat, metallurgy, hammering, sintering etc.
User avatar
Otaku19
Posts: 299
Joined: Fri Jan 27, 2017 5:43 pm
Has thanked: 1 time
Been thanked: 1 time

Re: Diamond stones

Post by Otaku19 »

Intriguing theory from a very accomplished sharpener: https://www.youtube.com/watch?v=WBoA8VI6koE
User avatar
lsboogy
Posts: 1486
Joined: Tue Jun 05, 2018 1:23 pm
Location: Minneapolis
Has thanked: 41 times
Been thanked: 132 times

Re: Diamond stones

Post by lsboogy »

Otaku19 wrote: Tue Mar 05, 2019 8:55 pm Intriguing theory from a very accomplished sharpener: https://www.youtube.com/watch?v=WBoA8VI6koE
I wish that a lab could back him up. I see many people who probably have valid points (sometimes known as craftspeople) who know more than the lab rats but have not found a way to validate what they feel. If we are talking about pulling out vanadium carbides from a well mixed steel, I would guess him wrong, but that's why steel is more than jello with bits in it. Metallurgy is still not an exact science - even VIMVAR stuff is not always uniform - we still get stringers in crucible melts where there should be none.
User avatar
Otaku19
Posts: 299
Joined: Fri Jan 27, 2017 5:43 pm
Has thanked: 1 time
Been thanked: 1 time

Re: Diamond stones

Post by Otaku19 »

I would really like to see the results from a very high powered microscope. I'm wondering if it's possible that the carbides are actually being dulled by softer stones versus being sharpened by the diamonds
User avatar
lsboogy
Posts: 1486
Joined: Tue Jun 05, 2018 1:23 pm
Location: Minneapolis
Has thanked: 41 times
Been thanked: 132 times

Re: Diamond stones

Post by lsboogy »

Otaku19 wrote: Tue Mar 12, 2019 5:17 am I would really like to see the results from a very high powered microscope. I'm wondering if it's possible that the carbides are actually being dulled by softer stones versus being sharpened by the diamonds
There are images of said in link above. I would not say that the no lab rats are wrong, but the lab rats have evidence of what they are talking about. If you look, carbides are about 50nm (vanadium carbides) in size. They are not well bonded in steel, but iron carbides (martensite, austentite, cementite) are not going anywhere, I think the idea that you pull carbides off a surface selectively near impossible - I'm not a metallurgist, but have a lot of surface science background and do a fair bit of metallurgy at work (physicist, with good background in material science). If your grain structures are bigger than 100nm mesh (where good powder steels start) you might have a case.
User avatar
ken123
Posts: 5342
Joined: Wed Jan 25, 2017 2:53 pm
Location: Northern California
Has thanked: 253 times
Been thanked: 316 times
Contact:

Re: Diamond stones

Post by ken123 »

Im just not that good of an advertiser :)

I have a 3000 grit diamond plate that I've been selling for a while.

---
Ken
User avatar
ken123
Posts: 5342
Joined: Wed Jan 25, 2017 2:53 pm
Location: Northern California
Has thanked: 253 times
Been thanked: 316 times
Contact:

Re: Diamond stones

Post by ken123 »

20190226_123832.jpg
3k diamond plate 3x8". Other sizes available for Edgepro, etc. Call for details.

---
Ken
Kalaeb
Posts: 3271
Joined: Thu Jan 26, 2017 8:59 pm
Location: Wisconsin
Has thanked: 208 times
Been thanked: 390 times

Re: Diamond stones

Post by Kalaeb »

I won't get into carbides or pull outs or anything but can say I return enjoy my 1k and 6k diamond for my pm steels. Sure, I probably can use naturals, but the diamond is just so fast and efficient. Plus the 6k leaves a great edge.

My curiosity is peaked by that 3k stone...maybe a one stop shop for a travel bag...
old onion
Posts: 897
Joined: Tue Sep 19, 2017 5:09 pm
Location: N.E. Ohio
Has thanked: 14 times
Been thanked: 4 times

Re: Diamond stones

Post by old onion »

My highest grit diamond plates is 1500 grit on my guided system and the knives that I use it on for my final have S30V , CPM S110V, CPM S35VN and CPM 20CV and I can not imagine those knives getting any sharper. It does a fine job. Mind you,I can not tell you what my carbides are doing but then ( "you can't see them from an airplane").My Dad's old saying.
Post Reply