Sharpening stones to use with modern powder steels

[maximus83]

What stone type or combination of stone types have you found most effective to sharpen super hard modern steels of the powder steel type?

Examples: S30v/S35vn, CTS-XHP, M390/20cv, Elmax, S90v/S110v

Background: Have used 100% diamonds on all blades of these types I've had within the last decade. Recently experimented using AlOx stones, they sort of worked, but the type I tried were not optimal on these steels, and after researching this more, I learned there are good reasons you probably don't want to use AlOx stones with these type of steels. Also experimented with SiC stones (used Congress Tools stones in the Sharpmaker, those worked fine on M390, S30v, S35vn). I've seen some pro sharpeners make the case, as mentioned here on the Hapstone site, that using diamonds with powder steels can have some challenges. Like micro-chipping, and deep scratches. I've observed the scratches issue firsthand in my own knives, mainly at low/coarse profiling grits, not at higher grits. I'm speculating about what would be a better, more optimal combination of stones to work with these steels.

Would it make sense as a sharpening strategy for these steels to do profiling and coarse work at lower grits with SiC stones (say a Norton Crystolon combo stone 120/320), and then do your finishing work with higher grit diamonds, say something in the 1000/1200 range for apexing, and something 6k/8K range if needed for polishing?

 

[Mo2]

I use SiC, diamond, bonded diamond. Have used ceramic many times in the past but have avoided using it recently on super steel, but works great on lower end steels. I've got a smith's fine ceramic and spyderco Sharpmaker and of course the famous button of a mug.

Bonded diamonds are my favorite but SiC is next best. Generally use a working edge but have gone much further occasionally depending on what I'm cutting and the steel.

I generally stick to one or the other. Primarily due to the difference in stone thickness and having to adjust the edge pro or kme to the different stones. Tho I'm probably going to be experimenting with diamond strops vs the SiC strop I use now.

 

[miso2]

I would use diamond to lower the edge angle, as the stone would not touch the apex until the very end.

 

[HeavyHanded]

You could certainly use SIC stones to reset the bevel and then switch to diamond at higher finish levels.

Personally I haven't seen any issues with microchipping or even deeper scratches on PM steels with my diamond plates. I normally reset with an XC DMT and once that's done I fly through the following progressions.

I have an innate aversion to applying a lot of pressure though, as I want to spare my diamond plates as much wear as possible. I also tend to go "heavier" on the trailing portion of my pass, and lighter on the leading portion to help with diamond tear-out. This is going to help with deeper digs in the steel too.

FWIW much of the chip effect can/might be be from slowly leveling deeper scratches, so avoiding deep scratches is very helpful.

Another consideration is SIC stones and all stones that release grit will tend to feather up the shoulder transition whereas diamond plates won't (as much). If cosmetics are a consideration then SIC maybe not the best choice to reset the edge either, esp on black coated blades.

 

[maximus83]

You could certainly use SIC stones to reset the bevel and then switch to diamond at higher finish levels.

Personally I haven't seen any issues with microchipping or even deeper scratches on PM steels with my diamond plates. I normally reset with an XC DMT and once that's done I fly through the following progressions.

I have an innate aversion to applying a lot of pressure though, as I want to spare my diamond plates as much wear as possible. I also tend to go "heavier" on the trailing portion of my pass, and lighter on the leading portion to help with diamond tear-out. This is going to help with deeper digs in the steel too.

FWIW much of the chip effect can/might be be from slowly leveling deeper scratches, so avoiding deep scratches is very helpful.

Another consideration is SIC stones and all stones that release grit will tend to feather up the shoulder transition whereas diamond plates won't (as much). If cosmetics are a consideration then SIC maybe not the best choice to reset the edge either, esp on black coated blades.

Super helpful, thanks. I think maybe in a few cases--as often the case --I get too aggressive, use too coarse of a stone, and maybe also too much pressure. For instance, profiling an edge on one of these blades recently I started with the Atoma 140, which I think maybe in hindsight was way overkill. I'll try starting with the DMT XC again even for profiling.

 

[adamlau]

Straight SiC or SiC with a high-grit diamond apex. Save those costly diamonds until the end.

 

[maximus83]

Straight SiC or SiC with a high-grit diamond apex. Save those costly diamonds until the end.

So, reviving this thread, and this idea we've talked about in a few threads and currently. The issue: What is a complete, but still basic and affordable, freehand sharpening setup for a beginner to be able to sharpen all knife steels, including high carbide (HC) super steels?

I'm interested in trying to come up with a variety of good answers to this question that would work for beginning sharpeners, or sharpeners like me who still want to keep a minimal setup, but want to add a few more capabilities to their setup beyond just a single Norton economy stone or something like that.

Here's one minimalist configuration I'm going to experiment with, using stones I already have. This approach involves heavier use of affordable SiC stones at the coarse end, and diamonds at the fine end, as Adam suggests. This uses SiC for what it's good at, and helps keep the overall cost of the sharpening setup down for a beginner.

• For heavy profiling, bevel setting, and coarse apexing: Norton Crystolon 8" bench stone, 120/320 grits. $24. The idea is, to keep things simple and cost effective, recommend this as the coarse stone for all initial coarse sharpening tasks, regardless of steel type. Some blades/steels, you may even be able to just finish and stop on the Norton fine side of the Crystolon, at 320 grit.
• For higher quality, all-purpose apexing/refining/finishing of all NON HC steels: Arctic Fox Bench stone, 400 grit. $40. This stone is your SAK stone for all sharpening of all knife steels other than super steels. I already use this stone this way, and I only go on to higher grits finishing stones like the Ptarmigan because I can, and it's fun, but I don't need the extra stones to get a sharper usable edge.
• DMT 8" EF diasharp continous plate (1200 mesh): $55. This works for finishing HC steels, or really finishing any type of steel at all, when necessary. As above, usually the Arctic Fox is adequate for finishing all my kitchen, utility, simple carbon steels.
• Stone holder: $35, or $25. For the $35 option, the Suehiro stainless holder. Or for the $25 option, get the DMT magnabase stone holder + adapter, holds your DMT diamond plate, and you can set other regular stone on the base and sharpen from it. I'd strongly recommend one of these two holder options, either one is superior to anything else I've used or seen for basic sharpening.
• Stone lapping option for the AF and Norton stones: search sk11 diamond at Big River, you can find a 150/600 grit 8x3" dual-sided diamond stone for $29 you can use to lap your AF and Norton stones when needed. And you can use it for sharpening, it works surprisingly well giving you 2 additional diamond grits.
• Strop: many many options here. Here's one I like after trying quite a few. It gets fantastic results, is simple to setup, strops all steel types, and keeps the cost down. An $8 2x2x12 basswood block. $13 for Kent Supplies 10 micron oil-based lapping paste. Sand the block, smear a couple drops mineral oil and a small amount of the paste on the block. This puts hair popping edges on all types of steels I have, from 420HC to M390.

There it is: total, end-to-end basic sharpening setup, covers all steels, only takes 4 stones, and includes everything you need. $205 total, assuming the Suehiro stone holder, and excluding shipping and taxes. Somebody serious about freehand sharpening could start with this, do really well and learn, and still build on the system later by adding more coarse stones, or more high-grit finishing stones, or stones of more premo materials like Shaptons.

I'm going to experiment with this setup a bit, since I already have everything in it, and see what kind of results I can get limiting myself to just these stones.

 

[jpm2]

My standard dull knife routine for the past 30 years is pretty simple.
Norton coarse Sic oilstone (2x8), Norton fine SiC oil stone (2x8), Eze-Lap fine diamond (2x6), bare denim (pants leg).
90% or more of the work is with coarse SiC.
There's some variation at times with more or less refinement, or experimenting, but the above covers 90% of my starting from dull sharpening sessions, with all knives and steels.

 

[David Martin]

You could certainly use SIC stones to reset the bevel and then switch to diamond at higher finish levels.Another consideration is SIC stones and all stones that release grit will tend to feather up the shoulder transition whereas diamond plates won't (as much). If cosmetics are a consideration then SIC maybe not the best choice to reset the edge either, esp on black coated blades.

I've noticed this on the Ti nitrite coated blades. I don't finish at higher levels. Still, some do-- so good point.
jpm, I do nearly the same routine. I came into sharping thru meat cutting. Hence, have used a Tri-Hone for near the same amount of time.
About 7 years ago I added a xcoarse and coarse diamond stones to my Tri-Hone. These 2 stones cost as much as the box and all the oil stones.
I also added a 4-500 grit SiC stone. Which I mostly use for the final burr removal. I wish I had gotten this stone years ago. A great stone. Still, the coarse stone is the work-horse. DM

 

[Yonose]

I use the 5” dmt fine(red), then extra fine (green), then a single spyderco ultrafine triangle “stone.” Gentle touch, and just a few strokes, alternating sides with each stroke on each level. Total cost $50, and s30v, CT’s-204p, s35vn, my daily users, all come out painlessly dry shaving my beard, or tree topping sharp

 

[jpm2]

I also added a 4-500 grit SiC stone

I would love to have one of these, where can I get one.

 

[Chris "Anagarika"]

I use the 5” dmt fine(red), then extra fine (green), then a single spyderco ultrafine triangle “stone.” Gentle touch, and just a few strokes, alternating sides with each stroke on each level. Total cost $50, and s30v, CT’s-204p, s35vn, my daily users, all come out painlessly dry shaving my beard, or tree topping sharp

Very similar to my setup, with DMT EEF often replaces the UF if dealing with the high vanadium carbides.

 

[mycough]

Some good info here, good to see the old dogs still helping out.
That's what makes this a great site!

Russ

 

[David Martin]

I would love to have one of these, where can I get one.

jpm, I got mine just about new with it's original box. It was made in the 70's by the Carborundum Company in Niagara Falls, NY..
It is labeled 'Fine'--118S a 2x4" stone. They can be found in different sizes on the bay. They box will note the information your after.
Mine had no smell of oil and was not dished. Good luck, DM

 

[maximus83]

I would love to have one of these, where can I get one.

@bluntcut in another thread pointed to a 2-grit SiC stone 400/1000, search "sharp pebble stone" at big river. If I were in the market for more Sic stones right now, I'd try this one.

 

[maximus83]

I use the 5” dmt fine(red), then extra fine (green), then a single spyderco ultrafine triangle “stone.” Gentle touch, and just a few strokes, alternating sides with each stroke on each level. Total cost $50, and s30v, CT’s-204p, s35vn, my daily users, all come out painlessly dry shaving my beard, or tree topping sharp

Nice! I like that minimal setup, a lot. +1 on using hte UF to refine. What do you use on the coarse end if you need to do a more significant edge profile?

 

[maximus83]

My standard dull knife routine for the past 30 years is pretty simple.
Norton coarse Sic oilstone (2x8), Norton fine SiC oil stone (2x8), Eze-Lap fine diamond (2x6), bare denim (pants leg).
90% or more of the work is with coarse SiC.
There's some variation at times with more or less refinement, or experimenting, but the above covers 90% of my starting from dull sharpening sessions, with all knives and steels.

Yep sounds good with SiC low-end, diamonds on the high-grit end. Checked the cost of the Eze-Lap 2x6 fine, around $30, so if buying today you could get that and the Nortons for around $76. I noticed they also have a 2x6 2-sided with 400/1200 for a few extra $. Sweet setup that kind of validates the idea of SiC + diamonds for general purpose. Another setup I'm checking on another thread, that is also super cheap and works good for Sharpmaker users, is Congress Tool Sic stones for Sharpmaker, plus the SM ceramics to micro and finish. Seems like SiC is a great option for the coarse end of the spectrum.

 

[jpm2]

M maximus83 , I might have mis stated "fine SiC". Mine are jb8 double sided and suspect they're more like coarse/medium. Neither of them are made in mexico, so they might be different.
The Norton jb8 and Eze-Lap 61F should come in around $50. Knifecenter has good selection and prices.
Yeah, if I removed metal at the same rate with diamonds, as I do with SiC, the diamond plate won't last long. My diamonds are mainly for touch ups, truing, and crisping the edge after a full sharpening.

 

[Yonose]

Nice! I like that minimal setup, a lot. +1 on using hte UF to refine. What do you use on the coarse end if you need to do a more significant edge profile?

If one of my pm steels were to chip or a needed a reprofile I have a dmt blue keychain stone (another $10). For non-pm steels I’ve got waterstones, but that’s a whole other thread!

 

[Yonose]

Very similar to my setup, with DMT EEF often replaces the UF if dealing with the high vanadium carbides.

I’ve used the eef in the past with mixed success, it takes more time on the uf but I think it comes out better. I’m not sure if it’s because the high grit of the eef is “overkill” for practical use though? Of course stropping compound works as well for a mirror polish