Silicon carbide stones

dkb45

dkb45

Joined
Dec 16, 2012
Messages
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I am looking to get some stones to give me another option to my Worksharp, and I know SiC stones can work on any steel (hell, I have even heard they work on ceramic!), so I figured I would check a hardware store for some... I ran into an issue, though. Not a single stone I could find had any mention of grit, just vague terms like "coarse" and "fine", which every knife nut knows are HIGHLY subjective terms. coarse could mean anything from 80-400 grit, and fine could be anything from around 100-10k grit. I know the 10k is a virtual impossibility, but it was for a point.

I want a coarse (~100 grit), medium (~200-400 grit), fine (1k or more if possible), and even finer stone. I know wet/dry sandpaper can be SiC (or AlOx), but I want stones, if possible. Do the stones I want exist? Are they less expensive than an arm and a leg? The stones don't *have* to be SiC, I just want something that can work decently on super high end steels, but not diamond, if possible (DMT stones are expensive as hell).
 
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It's coarse, not course-of course.
Get a Norton fine India stone.
 
Shapton pro or Shapton glass would be your best bet. Harder and slower wearing than a SiC stone with a grit range from 120-30,000.
 
If you're looking specifically for silicon carbide in finer grits, just use the wet/dry paper. Most SiC stones will only be found in coarse or medium grits (relatively), as compared to the higher finish afforded by the wet/dry paper in grits of ~400 and higher. A 'medium' or 'fine' stone in SiC will likely mimic something like 320-grit wet/dry paper, in terms of finish left (something of a coarse 'satin' finish). If you're looking for a finer finish, or polish of any kind, you'll need wet/dry paper at grits of about 400-800 (varying degrees of satin) to 1000+ (starting to polish).

The finest grits of wet/dry sandpaper are sometimes aluminum oxide (usually the 'grey' wet/dry paper, as opposed to SiC's distinct 'black'). Nothing wrong at all, with that; they work very well for a polished finish, down to sub-micron grit sizes at times.


David
 
I think Norton Does make finer SiC grit stones. Mostly what one sees is coarse= 100 grit, medium= 240 grit. I think HeavyHand found some finer SiC grit stones up to 5-600 grit. For a fine level. Check with him or leave him a message in his profile. DM
 
Below is an image snip from a Norton product catalog. The 'Fine' Crystolon (their SiC line) is graded somewhere between P320-P360 grit, as compared to FEPA-P standard for sandpaper; alternatively, it compares to 45µ diamond compound (equivalent to DMT's 'Coarse'), also seen in the chart. For something finer, their aluminum oxide 'India' stones are equivalently graded up to ~P800 for the 'Extra Fine' India, or 600 JIS (comparing to equivalent waterstones). Some of Norton's waterstones go quite a bit finer, up to 8000 JIS.

Norton's product catalog linked here -->: http://www.nortonstones.com/uploadedFiles/SGnortonstones/Documents/Sharpening Stones Catalog number 200 2008.pdf


David
 
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The SiC (Carborundum stones) were developed to sharpen WC (Tungsten Carbide) which Rockwells at 72C.View attachment 438844 If you get a Norton Trihone, it comes with 100 and 220 grit SIC stones (coarse and medium) and a 320 Al2O3 (Corundum) fine stone.
 
Jason B. said:
Shapton pro or Shapton glass would be your best bet. Harder and slower wearing than a SiC stone with a grit range from 120-30,000.
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I checked on those, and bloody hell nope. Way more expensive than I can afford. More expensive than I will likely ever spend. Those diamond stones are looking a little bit better now...
tiguy7 said:
The SiC (Carborundum stones) were developed to sharpen WC (Tungsten Carbide) which Rockwells at 72C.View attachment 438844 If you get a Norton Trihone, it comes with 100 and 220 grit SIC stones (coarse and medium) and a 320 Al2O3 (Corundum) fine stone.
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Interesting. I didn't think the stones would be SiC. I already have a XC DMT stone, though. These wouldn't be too much of a grit upgrade, sadly. I wish more store-bought sharpeners didn't consider something as coarse as 400 a fine grit. To me that is a coarse or medium grit. It doesn't become fine until it breaks 1000.
 
The Norton tri-stones are coarse/medium SIC and fine india. You can pick up some of the Norton Combo stones in SIC and the India for relatively cheaply in comparison to the tri-stone setup if you don't mind not having their base which can hold oil for you. I use 2 of their economy stones a SIC and India and my grit progression is usually coarse/fine SIC to fine India and it works quite well. As mentioned earlier if you want to go higher grit for SIC you are more than likely looking at having to use sandpaper unfortunately.
 
DMT credit card goes for about 30$ for C, F & EF. With patience, it works on any steel ;)

I also have limited budget, therefore have similar need.
 
dkb45 said:
I am looking to get some stones to give me another option to my Worksharp, and I know SiC stones can work on any steel (hell, I have even heard they work on ceramic!), so I figured I would check a hardware store for some... I ran into an issue, though. Not a single stone I could find had any mention of grit, just vague terms like "coarse" and "fine", which every knife nut knows are HIGHLY subjective terms. coarse could mean anything from 80-400 grit, and fine could be anything from around 100-10k grit. I know the 10k is a virtual impossibility, but it was for a point.

I want a coarse (~100 grit), medium (~200-400 grit), fine (1k or more if possible), and even finer stone. I know wet/dry sandpaper can be SiC (or AlOx), but I want stones, if possible. Do the stones I want exist? Are they less expensive than an arm and a leg? The stones don't *have* to be SiC, I just want something that can work decently on super high end steels, but not diamond, if possible (DMT stones are expensive as hell).
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For a full range of silicon carbide abrasives, sandpaper is by far the easiest way to go. That said, I really don't like using them on anything but my Washboard as I find the surface just isn't as "crisp" as I'd like when using it over glass, steel, stone. Is very inexpensive to try out though, and as long as you keep the surface of the paper clean, it can last a long time. An eraser comes in very handy in is extremely convenient, or a few drops of mineral oil can work well too.

Razor's Edge Systems sells a coarse and fine stone that are very useful and can be picked up on the cheap from time to time when they list 2nds on their site. The fine is (just a guess) about 800 grit. Don't be misled by the grit rating on SiC stones, they are capable of edges much finer than the rating, and the mud they create can be lifted off on a sheet of paper and used as a very effective strop - further refining the edge with no further investment. Off the stone, the RE fine stone makes a real nice edge. I have consistently gotten the edges off my Crystalon stone (after being stropped on the reclaimed mud) to dry shave facial stubble and just tree top some leg hair.

If you are feeling adventurous, there is also the stones used to sharpen jointer blades while they are still in the machine. They range from coarse to medium, though toward the upper end of what I'd consider medium. An outfit called Global Tooling has a range of them, the most interesting thing about them is that they are made to be used at operating speeds on the given jointer blades (carbide or high speed steel) without oil or water, and are also made to be shaped to accommodate various blade profiles. In use, if used with mineral oil, they feel and work just like a waterstone with the added bonus they can be used dry for touchups until they begin to load up. I picked up a Norton 220 grit and a Tyrolit 500 grit. The 500 is more in the range of 800 grit or so in use, possibly a touch finer with some practice. Likewise the mud can be claimed to make a stropping slurry. I can get you the order #s from the stones I bought as there's a page to choose from and few guidelines of use to the freehand sharpener. They are meant to be consumed in the process and so are fairly inexpensive, $20 or less per stone.

Lots to choose from but ultimately the Norton Crystalon stone or my Washboard would be my best recommendations. In a pinch, the combination stone sold at ACE hardware is a good tool as well - very inexpensive, made in USA, and a nicer quality than the Norton Econo stone.
 
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wonder why no one is mentioning congress. they have a wide range of sic stones, not to mention other types such as alox, ceramic, and diamond. they're much more affordable than the Japanese water stones I've seen.
 
bodog said:
wonder why no one is mentioning congress. they have a wide range of sic stones, not to mention other types such as alox, ceramic, and diamond. they're much more affordable than the Japanese water stones I've seen.
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I've never used them but would have put in a plug based on the good rep they have around the forum. IIRC they don't come in sizes larger then 1"x6" - not a very convenient size for freehand in most cases, though some have reported doing so. Am pretty sure even those come in no grit (in SiC) finer than 600 but could be wrong.
 
HeavyHanded said:
I've never used them but would have put in a plug based on the good rep they have around the forum. IIRC they don't come in sizes larger then 1"x6" - not a very convenient size for freehand in most cases, though some have reported doing so. Am pretty sure even those come in no grit (in SiC) finer than 600 but could be wrong.
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When I started sharpening I used some puny 1.5x4 stones. 6" is more than big enough for me to use. I think I will try sandpaper to start with. I just never had good results, but starting with 80 grit could have been the issue, because it was leaving a ton of micro chips in the edge. The 80 I can get is also tan (making me think it is not AlOx or SiC).

Is an edge from 800 grit really capable of that level of sharpness without stropping (on a strop with compound) though? I have pretty much mastered the light touch, so that won't be an issue. Is that low of a grit really able to be that sharp?

Also, can a SiC stone be used with water? I don't really want to use oil if possible, both for mess and ease of transport (no special container needed for a dry stone). I know it will likely load up faster, but I'm fine with that.
 
A 800 grit stone is pretty fine to me. They are easily capable of the level of sharpness HeavyHand describes. I like to use oil on my stones and don't see much mess. DM
 
I have stones with Silicon Carbide in as fine as a 1k grit. If interested, just contact me. Having said that, I wouldn't limit yourself to SIC. You would be better served on abrasion resistant steels with CBN or diamond - even moreso than with aluminum oxide based stones. These are available over a wide grit range. You can also use aluminum oxide based stones and add a bit of CBN or diamond to the slurry to better deal with more abrasion resistant steels. Even so most of the steels you encounter can be sharpened with aluminum oxide based preparations until you start going into higher Vanadium content steels.

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Ken
 
As a rough estimate, 4 % although even abrasion resistant steels like zdp-189 with no vanadium are much easier to work with.

While you can do steels with this much Vanaduim carbide it is a comparative PITA to do so, especially if it involves any reprofiling rather than refining an existing edge angle. S30v would be an example. With diamonds or CBN, it's not a big deal. Just with stones, it's a good bit more work. When you start dealing with steels like s90v, most any good stone - including Nubatamas, Shapton Pro or Glassstones or Naniwa stones are an exercise in frustration to use. While SIC is slightly harder than aluminum oxide, it is just slightly harder and a modest improvement.

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Ken
 
I sharpen CPM S-90-V blades on SiC and Al2O3 stones with no problem. S 90 has about 24% carbides by volume including 9% Vanadium carbides at 82 HRC.
To avoid a mess when using USP mineral oil on your stones, squeegee the excess oil off the stone with a rubber kitchen spatula before sharpening your knife.
 
As a rough estimate, 4 % although even abrasion resistant steels like zdp-189 with no vanadium are much easier to work with.

While you can do steels with this much Vanaduim carbide it is a comparative PITA to do so, especially if it involves any reprofiling rather than refining an existing edge angle. S30v would be an example. With diamonds or CBN, it's not a big deal. Just with stones, it's a good bit more work. When you start dealing with steels like s90v, most any good stone - including Nubatamas, Shapton Pro or Glassstones or Naniwa stones are an exercise in frustration to use. While SIC is slightly harder than aluminum oxide, it is just slightly harder and a modest improvement.

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Ken
 
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