Waterstone testing, the results. Part I.

Hello again faithful reader,

This is not what you are thinking, because it’s the not the actual ‘results’, not just yet. I have some ‘splainin to do first…

Collecting the data and putting them into a form that is easily digestible is no easy task. Should I do each stone individually, and have you all search high and low to really compare stones? Do I run a comparison on each steel individually, so you can see what stone will work best with your blades? Do I stick them all in a blender, and hope for an understandable result?

In the end, to save you and me some time and effort, I’ll be putting the results in graph and table form for each type of steel used for comparison. I feel this will most easily allow you, the waterstone user to easily see which stone is right for you and your particular application. It will save me a lot of effort, since I can easily convert the massive amount of data into a compact form by simply moving numbers around. This will also give you vultures something to chew on, because I just know how antsy some of you are getting.

It’ll also buy me some time to make up a nifty little ‘flash card’ you can use to go shopping with. You will be able to simply print out each stone’s “Top Trumps” card, and compare them! Sounds like a game if only it wasn’t so serious.

Without further ado, let’s get cracking…

This first comparison takes in the number of average strokes for each stone to re-establish a burr on the back of each respective blade. A test of outright speed, nothing more…

Ever wondered exactly how much more difficult A2 is to sharpen than O1? There’s your answer right there.

Approximate surface area of the O1 blade’s bevel; 239mm2

Approximate surface area of the A2 blade’s bevel; 310 mm2

Approximate surface area of the Blue Chip’s bevel; 127mm2

Note; The two plane blades were dubbed with a single stroke across their width. The Marples chisel was dubbed with a downward pass, away from the back. In simple terms, the chisel was more severely blunted, reflecting the greater degree of edge damage that can occur with a chisel vis-à-vis a plane blade.

Now, let’s just look at this data for a minute. Take into account that the A2 blade’s bevel is 30% larger than the O1 blade, but 23% narrower and look at what’s going on. I don’t know about you, but in most cases, it looks to me that most stones only needed 30% more effort to abrade approximately the same amount of dubbing on the A2 blade over the O1. Granted this is at the medium/coarse end of the range but still, it appears to me that A2 (at least on these stones) isn’t much of a problem.

It also appears that the values appear to be all over the place, sometimes some stones have a nice, predictable increase in sharpening time, reflecting the greater amount of work to do. But stones such as the Naniwa Super Stone show an exponential rise in effort required, while the King Neo makes a hump.

You might think this is an error in the data, but I assure you it is not. At this juncture, we don’t have enough data to fully understand what’s going on here.

(I know why the King Neo put the pedal to the metal on the Marples chisel, and it’s not something to be happy with just yet…)

Now, while we have this nice graph showing, why not add the rest of the results for the remaining 3 Japanese steels?

Approximate surface area of the Blue steel chisel’s bevel; 98mm2

Approximate surface area of the HSS chisel’s bevel; 71mm2

Approximate surface area of the White steel chisel’s bevel; 146mm2

Note; the Blue steel and HSS chisels were dubbed in the same manner as the Marples chisel. The White steel chisel was dubbed by a pass over a 200mm long, #1000 grit diamond plate. Using the existing test, the chisel had a burr raised too quickly to separate the results.

Now, what’s going on here? Take a look at the results from the Blue steel chisel and compare them to the Marples chisel. While the Marples chisel presents a 30% larger surface area to the stone, it takes more than twice as long to raise that burr. I don’t know about you, but to me it’s saying, nay, screaming that those Japanese folks going to all that trouble to laminate their blades might just be onto something…

You’ve probably heard and read that “Japanese chisels are easy to sharpen” and I don’t think it gets any more graphic than that. But again, it’s not a direct comparison since the Marples does have a larger bevel on it. But twice as large? No, only 30% larger.

I’d also like to mention that the King Deluxe and Naniwa Super Stone have very high numbers on the HSS part of the graph. These numbers are not a true indication of their abilities. The fact is, the King was absolutely unable to do anything to the HSS chisel. The blade is so hard and tough that literally nothing happened to the stone. The Naniwa did abrade the steel, but was so slow and clogged so badly that it’s also considered a failure.

You might also be looking at the white steel chisel result and be asking serious questions about my sanity. Don’t forget that this was a torture test, so a lot of work was required to get the edge back into shape again. If I had done the same with the Marples chisel, I’d probably still be working away…

Before you start jumping to conclusions, this is purely a measure of how quickly each stone brought a deliberately blunted edge back to a point where it could be made sharp again. These results show only SPEED and nothing more. Because this battery of tests is to help us evaluate a stone in its entirety we need more data to even begin forming conclusions.

However, if you only care about how quickly a stone can get your tools sharp, pick a fast one for your blades and call be done with it.

For now, I’ll leave you with this small anecdote;

“Don’t judge a book by its cover”

Until next time, sooner rather than later,


Edit; I’ve altered the graphs to make them a little easier to read, I hope.

3 comments to Waterstone testing, the results. Part I.

  • Eric

    Ok, Stu, I have to ask. If you had dubbed the white steel chisel in a similar manner to the other chisels, what would the chart look like? Just a few strokes per stone?

  • Hi Eric,

    I’m glad you asked and might have forgotten to throw that little tidbit in.

    For comparison, take the blue steel results, reduce them by 50-70% and that’s what the white steel test would have looked like.

    I did actually test a few stones with a ‘standard dubbing’ but the burr was raised so quickly that splitting the stones would have required me to count single strokes over the stone. The variance just wasn’t large enough to compare anything. The graph probably would have looked like a plateau of 5-10 strokes for each stone.

    I always knew white steel on iron blades were easy to sharpen, but the truth is far more significant than I imagined. Just too easy, so a more severe test was called up, and I had that big diamond plate just sitting there, why not waste off a few mm of a nice chisel for a good cause?

    Besides, the flat on the back was getting a little fat…

    I may do a comparison in the near future of the various steels with a few stones just so a proper comparison can be made.


  • [...] subsequently its task for whichever given blade was completed. The number of strokes can be seen in part one, and in most cases the stone surface and bevel was [...]