Thread: Definition of Hardness in Water stones & Sigma Power Stones

I have the Shaptons not the Sigma, but both types are ceramic, and therefore probably comparable.

The Shaptons cut quite fast, but they have a very different feel from the softer King stones, and may take some getting used to. I've found they provide a better feedback through the blade to the hands. They do remain flatter for longer, but they still need to be flattened regularly, though obviously not as frequently as the softer stones.

I've never used the Sigma stones, but I would say they would be similar.

Des

Hi TS

Can't give you a definition of 'hardness' with waterstones, it's just a relative description mainly used with natural stones. Harder stones tend to be slower wearing (the particles break away less often to reveal fresh grit) and have, but not always, a finer grit size. They are the final polishing stone. You wouldn't try to raise a fresh burr with them, but polish the burr off. Rare natural stones can be both hard and aggressive (the particles don't break away but also retain their cutting edges for longer) but they come at a premium price.

Suggest you forget all about the Chinese waterstone, at least for now. It's not a good starting point for getting into waterstones.

I have some Sigma waterstones (1000, 2000 & 8000) and they do wear a bit slower than my Kings, but faster than my Naniwa. They say that the Sigma are better for high alloy steels, so may suit your A2 or M2 blades.

If you are looking in the lower grit range (I note you are only looking in the 8000 range at this stage), also consider a Bester stone, which is one of the hardest stones in the lower grits.

Having not used Shapton, I can't comment from experience, but understand the Pro ones sold in Japan stay flatter but also cut faster. Again a little bit more expensive than the Sigmas in the finer grit stones.

Natural stones are another story altogether....

No matter what the waterstone, I keep a diamond plate next to the stone and constantly apply the plate to keep it flat. The added advantage is the fresh grit 'mud' this creates which optimises the cutting power for that stone.

If you are shopping around, also have a look at Tools from Japan. There is a currency option button at the top of each page. The postage costs have to be factored in for any cost comparisons, which of course will have also been added already to any local suppliers.

Hope this hasn't confused you more than helped you, TS.

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Hock goes into this in his 09 book on Sharpening.

The only thing that stuck with me was re the Shaptons; in hardness they're mid rated.

Haven't had a chance to try mine yet.

But with M2 my assumption would be that diamond stones would be the way to go. Eg. DMT D8EE

I'll take another look at what Hock says if you like. FWIW

Edit: did that; all I can add is that he says hardness is a function of the binder.

I have ordered some sigma stones from Tools From Japan. I got them at a much better price then what Japan Tool list them at.

While feedback on the Sigma stones are limited, my impression is that they cut faster then most, give a very sharp edge, and do not dish as much.

I should have them in 2 weeks.

I will post a review of them once I get them.

Look forward to it. Thanks Helmut.

Helmut - those prices on the Tools From Japan site are certainly attractive for the finer grits of Sigma stone.

I'd be interested to know what methods they offer for shipping, and the approximate shipping cost for 1 or 2 of the Sigma stones. I have a feeling that they won't be that different to the Shaptons in terms of performance.

I currently use a Norton 4000/8000 waterstone for final honing. It gives good results, but is only slightly harder wearing than the King stones, so constant re-flattening is required. I'll be interested to hear what you think of the Sigma stones.

Mr Bush - It cost me AU $50 shipping for four Sigma stones weighing in at 4 kg's via Air Mail. The two week wait is due to the fact that Tools from Japan keeps no stock and so they source the stones and pass them on to the buyer.

Tools from Japan were fast to respond to my questions and very helpful.

Helmut, is that Stu from Tokyo?

I was wondering the same thing.

The guy from Tools From Japan was an Australian and his name is Stu.

Doubt that there would be many Australian living in Japan both being woodworkers and both being called Stu.

So it is Possible.

Stu from Tokyo and Stu from Tools from Japan are not the same entity.

Here is one: Stuart Ablett's Workshop

The other: Tools from Japan blog.

I asked Stu for some information on the stones this is what he sent me.

Well, starting from the low grit to the fine grit, here's how they work.

The #120 is one of the hardest coarse grit stones going. It will do a lot of work before it needs flattening, and I am of the opinion that if you can manage your sharpening well, you will never need to 'flatten' it. Besides which, it's a rough stone and is only really used for getting blades into shape.

The #1000 is again one of the hardest medium stones going. It should not require 'soaking' but a dunk in some water for a minute is not a bad thing. They soak up water very rapidly, and if you let the stone get too dry, it will clog a little and give a finer finish. But since you have the #2000 coming as well, keep it wet as much as possible. A squirt bottle of water will be a great help, just a shot now and then to keep the surface clean and swarf free. The #1000 does remove metal at a good rate, depending on the steel as well as a Shapton and stays even flatter. But if I had a choice, I'd choose a Bester #1000. The Bester do need soaking, but again it's only a minute. Just as hard as the Sigma, but the Bester chews metal up like there is no tomorrow. (And if you want to switch to the Bester, no trouble at all.)

By comparison, my

The #2000 is very similar to the #1000, but backed off a little in aggressiveness and speed. A dunk in water should be enough, and then keep the surface wet. Not much more to say, it's a 'refined' Sigma #1000.

This is personal opinion though. You may find they work better for you with just a splash of water or by leaving them in a tub for 5 minutes. I can tell you that compared to my old King #1000, these things are a dozen steps ahead everywhere, except maybe for outright speed. The King is about as fast, but you really need to be on the ball to prevent the King from dishing excessively, where the Sigma stones need far less attention. And the King needs to be submerged in water for at least 5 minutes, and then kept wet all day. A right pain really, but since I inherited the thing and it works well, I can't manage to convince myself to use anything until I wear it out. I am halfway there now after a couple years, so another couple solid years of use might see me looking for a new stone.

(Or it might have an imaginary accident with a hammer beforehand...)

The #8000 is not as hard, and is more conventional in it's composition. It only needs a splash before working, and is quite similar to a King #8000 except that it was formulated for tougher steel alloys rather than plain carbon steel like White steel and W1. It is 'quite' soft, but as it is a fine stone, that shouldn't be a problem and it will resist dishing very well. Maybe not as hard as a Shapton Professional #8000, but faster and resists dishing in the bargain.

Sigma happens to make and sell cooking knives, and these stones are designed for their knives, many of which are stainless steel and similar tough alloys, so they also produce a range of stones to get and keep their knives sharp. Just lucky coincidence that they work well sharpening all manner of blades and they are priced well too. It is quite common for professional carpenters here to go from the #1000 to the #8000 because the intermediate stone isn't really required for simple carbon steels as they often use here. The Sigma stones also work very well with the newer HSS planes and chisels that are becoming common here which are used on questionable and abrasive materials during renovations and new pre-fab construction.

Which brings me to a little tid-bit of information I discovered only today...

I read a few things, and ended up putting two and two together and, well, what do you know about M2 HSS plane blades?

You may not know this, but special sharpening stones do exist for HSS woodworking blades. King make a brace of #1000 stones, and I have them listed in the store. Sigma also make a pair of sharpening stones, one is @ #1000 and the other is 'fine' and they are a matched pair for HSS, but are available separately. They also make a special 'carbon' stone that uses a carbon based binder which is very tough, and the stone is graded at #700 grit. The #700 does not have many fans, but the pair of Sigma stones (sold as 'Select II) are quite well thought of.

Other stones do exist solely for HSS tools, but I am not as familiar with them as I am with the King and Sigma. The glut of diamond sharpening plates and stones (I only have plates listed thus far) have also been developed with HSS in mind and many are fairly recent products here, especially since HSS tools have only taken off in the last few years. Previously Blue steel was the 'tough' steel, but it didn't need any special sharpening methods.

Well, that's my thoughts on the Sigma stones. I really like them and I manage to sell quite a few of them with no complaints so far. As you might expect, these are rarely the first water stones for those who do buy them, so those who use them do have a basis for comparison.

I hope that helps, and I hope to hear back from you soon as I have the #120, #1000 and #2000 here ready to leave, and was planning on getting at least 2 of them out tomorrow. The #8000 stones take a long time to come in, and I am expecting it in the next couple days. I usually keep one on the shelf because they do take so long to get a hold of, but the last one ran away recently and I hadn't managed to get another in the mean time.

Thanks TS for passing on that very useful info from Stu.

May have to take a closer look at the Besters (just don't ask how many stones I have already)...

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Here is some more information from Stu regarding polishing stones in the 10,000 plus range.

While the Sigma #1000 is a great stone, I do believe the Bester #1000 is superior, and it's even a little bigger. The price difference is only 300 yen, and there may be that much difference between calculated and actual shipping costs (I always refund any extra shipping charges) so there may be no cost difference. If there is a difference after that, I'll cover it myself. If that works for you, let me know just to confirm it please.

With regard to the #8000 grit, I honestly believe that beyond this stone, you are looking at diminishing returns. Any #8000 stone will give an edge that is sufficient for most edge tools, most of the time. If a sharper edge is required, then how you get it should be decided by whichever method suits you best. This could be stropping, polishing with compound or a finer grit stone. Unfortunately, beyond #10000 grit the choices are limited because, as I said, beyond this point the need for something sharper is quite small.

I also think that with the Sigma #8000, any #10000 stone is not a big enough jump to warrant the money. Sounds odd since I am selling stuff, but I don't want you (or anyone) to feel short changed in any way. If you did decide to go with a finer waterstone, then it should be either something really special in #10000 grit, or something much finer than #10000 grit.

The current Sigma #10000 stone is in the same 'model line' as the #1000 and #2000 Sigma stones I list, the #8000 is not. What is strange is that many people are convinced that the #10000 was previously labeled #8000 grit. I cannot confirm or deny that, but the difference between the two is quite small in real terms. Very much a case of one or the other, but usually not both.

The Naniwa #10000 Superstone is, again, not a big enough improvement in my mind over the Sigma #8000. What you do need to realize is that the Sigma #8000 is above average. Not as hard outright as a Shapton Professional, but faster, thicker and resists dishing very well, which makes it a popular choice here. But the Sigma #10000 is just as popular...

The Naniwa Chosera (Ultra Ceramic) is a big enough improvement over the Sigma #8000, but they are not inexpensive either. From me, one would be 24995 yen plus 1000 yen or so for basic SAL/Small Packet shipping. Tools for Working Wood has them on sale right now, for US$225 or so, and if the shipping works, I'd have to tell you to take them up on it if you wished to use one of them.

The Shapton Professional #12000 might be enough of an improvement, but I wouldn't be confident in that statement until I had to the chance to compare them back to back.

The Shapton Glass stone in #16000 grit would most certainly give a sharper edge, they are very hard and strongly resist dishing, but they are very thin (5mm or so of usable material) and quite expensive at @9500 yen from me, and I don't have them listed yet, but I am considering it very strongly since outside North America, they are difficult to find. It would be a Japanese market Glass stone which are different to the American version, being specifically suited to Japanese blades. It was said that there was a difference in Pro stones too, but few could notice it. The difference between the American and Japanese Glass stones is easier to feel. Because they are not heavy, they cost about 600yen to ship via SAL/Small packet. Of course there is also the #30000 Glass stone at @26500 yen, but the jump to that is too far from the Sigma #8000 unless you are using a very small microbevel and actively work to keep it very small.

Another useful slab of info, thanks TS.

Stu hasn't mentioned natural waterstones for grit sizes above 8000. They are not exactly a consumer product and perhaps not normally used for M2 steel, but they are in my opinion the next step if you want to go beyond #8000 and not want to go down something like the diamond paste path.

However I would be seeing how you like the edge off the #8000 before thinking of anything finer.

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