Sigma Stones

[David Weaver]

With what you've stated, you'll be best off with the bester/imanishi stones if you want to go with a soaker, shapton pros if you want to avoid soaking.

All of the stones you've listed will cut A2 and O1 without issue.

The sigmas that LV has are geared toward high speed steels, and it appears from all write-ups about them that they take care of high speed steel with efficiency maybe similar to diamonds, but they are soft stones and the speed difference on high carbon steel will not be nearly as much - not enough to warrant the extra flattening they'll require.

I have used (own or owned, actually) bester, naniwa super stones and shaptons, and all of them cut everything you've listed with ease. I can't comment on the imanishi stones unless they are like the besters. Besters are porous, thirsty (but soak quickly), fast cutting and stay flat for a long time. For practical use, I still like the shapton *pros* the best (not that excited about glasstones). No soaking, meaning if you're in the shop for a half hour, you need no forethought to use any of them - you just go to them, spritz the surface and sharpen. They cut A2 and high carbon steel as fast or nearly as fast as anything, leave a very uniform scratch pattern at the edge, require little flattening, and are ready to use as fast as you can squirt a mist on them. They also obliterate any traditional japanese tool steels (the white, blue and boutique blue steels).

There are US and japan market stones. I have some of both. I can't tell a difference. There is a huge difference in price, though.

*I think* Shapton says that the 12k is a 1.2 micron stone and the 15k pro is 0.98 micron. You will not be able to tell a difference in use if there is one, and the 12k stone can be had for as little as $85 shipped if you look around (ebay, etc) and get it from japan. If you use microbevels or hollow grinds, the 1k and 12k are all you would ever need, and if you want to go finer than that (I don't know why you would for woodworking), you could go straight to LV green stuff on MDF. I am not aware of an artificial stone that will create an edge superior to the green stuff on mdf, and I have used the shapton 30k stone (which I think is generally a waste of money unless you're in a contest with someone).

There's nothing wrong with soaker stones unless you like to work like I like to work (I may have an hour here or there to work sometimes, and I have no interest in soaking stones or dealing with grit contamination on my fine stones or putting them in separate containers to avoid that. I like sharpening to be a sub-minute activity).

The shaptons are very hard and non-porous and do a good job of allowing you to work in both directions if you work freehand - without much concern of gouging the stones. They have some stiction and are a little more dense on the surface than a soaker, but technique overcomes that easily. You can sharpen a hollow ground chisel extremely quickly on them by working the chisel in a side sharpening pattern through the fine stone and then taking a few short strokes with the finest stone to get the scratches perpendicular. I would say from the time I arrive at the stones to the time I walk away with a hollow ground chisel that starts fairly dull, it's probably 30 seconds to hit the bevel 1k and then 15k, and lap the back about 10 strokes.

The only other way to match that kind of speed is to use diamonds, and I'm convinced the edge isn't as fine with them in a two step process, and the scratches aren't nearly as uniform.

The naniwa superstones are a lot the same, but they don't cut quite as aggressively and are a lot smoother to use - the feel of them is almost like a medium hardness natural stone (i understand naniwa worked to get that feel on purpose). The shaptons will cut HSS with some skill (they will make it sharp, they will not hog it like diamonds, but they will make it sharp just fine with microbevels or a hollow grind - you don't want to have HSS without the ability to power grind, anyway), but I hear the superstones won't do it so well. I never tried the one I had on HSS.

[Jessica Pierce-LaRose]

The naniwa superstones are a lot the same, but they don't cut quite as aggressively and are a lot smoother to use - the feel of them is almost like a medium hardness natural stone (i understand naniwa worked to get that feel on purpose).

Makes sense. I recently ordered three of the Naniwa Superstones; it says "Fine sharpening-taste as natural stone gives." on the packaging. Makes sense now.

[James K Peterson]

How well do the Sigma Power Stones cut D2, cpm-v3, and cpm-v10? I'm hoping to get some Ray Iles D2 plane blades, and as soon as John Payne is able to get his chisels and blades through testing and into production, I'll have some great cpm-v10 blades
I'm just trying to get setup for sharpening those hard blades. I think diamond paste on a steel plate would work to cut those hard edges.

I've read some great stuff from Stuart Tierney blog where he's testing a bunch of stones. But I'm just not sure what to make of the results so far. But it does look like the Sigma Power Select II are good for the hard metals, I'm just not sure if the higher grit sigmas are good for the hard metals (3000/10000).

Anyone have some advice on what to try on these new hard metals?

[David Weaver]

I would imagine the entire line is good for hard metals, that's what they're designed for. It looks like stu cut the entire flat bevel with the 1k stone, which is something no sane person would ever need to do, but it does show that they cut aggressively. Even if the higher stones are a little less aggressive, they should have no trouble. If stu's recommendation isn't enough, the fact that LV decided to offer them to cut their HSS irons should be convincing.

Diamonds on steel will cut anything, including carbide - you will never find a steel that diamonds don't obliterate. Even when you hone HSS on a diamond hone, it files it off like it's plain steel. Nothing cuts deeper or faster than diamonds, but you have to try them and see if you mind the feel. I like a stone better, there's something missing from the feel on a steel plate.

I have the RI D2 mortise chisels and they are no problem to sharpen on shapton pros or a muddy kitayama stone I have. they are not close to as difficult to sharpen as M2 HSS.

The harder the steel, the better the idea to use power sharpening to do all but honing a small area, no matter the stone. Microbevels or a hollow grind, and of what you mentioned, a lot of stones should handle everything except maybe the V10. I saw reading WN that someone with a lot of experience had no issue using plain old kings for V3.

[Mike Holbrook]

I just placed an order with Stuart (Stu) at Tools from Japan recently. I am hoping that Stu is ok since I assume he was in Japan during the disaster. I want to be able to cut the new tougher metals too.

I ordered:
1 x Sigma power ceramic stone #120
1 x Sigma power ceramic stone, 3F Carbon #700.
1 x Sigma Power 'Select II' ceramic stone, #6000 grit.
1 x Sigma Power 'Select II' ceramic stone, #10000 grit.
1 x Suehiro 'Free size' waterstone base, single rod with tray.

I have a Shapton 2000 Pro stone that I purchased way back when the 1000's spent a long time out of stock. The Sigma power Ceramic stone, 3F Carbon #700 is a unique stone in that it cuts much more like a Select II. Stu felt that the Select II stones in the higher grits do not have the same softness/wear issues that the lower grit stones suffer from but cut just about any steel faster. I think the Sigma Power (SP) stones that Stu sells are an improvement over the Bester stones.

I had a problem with one of the two Shapton stones I bought, a #8000 Pro. It took a fall and broke into pieces. The Sigma stones are much thicker and tougher than the Shapton stones, which is the main reason I went with them.

I am sending all the good vibes I can toward Japan.