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The confusion with grain may be even worse. A hard bonded stone releases grain more reluctantly than a soft one. The latter will offer freshly released sharp grain more eagerly.

Hard stones are said to be more forgiving for this reason. Besides that, such a stone gives a different grinding surface pattern, suggesting a finer grain than there actually is.

To return back to the point of the original subject, I think the SG-2x0 is too coarse for knife sharpening overall and for what the Japanese call "the middle stone", despite all dressing measures.

I am ready to believe that it makes micro-serrations and thus yields a subjectively perceived good cutting action fast, but it may get there too fast for its own merit in unexercised hands (me not excluded).
It was meant to be the end-all solution for all cases, which cannot be.

BTW, I don´t see a comparably small company like Tormek genuinely producing their own stones. There are time-honored companies that do nothing but that.
And you would be surpised how cheap a custom job is, even at low quantities...

This is also why switching between manufacturers stones/wheels can be problematic as you work up in finish is that without the actual micron range you can be way off.

Totally agree. Even their own blackstone (silicon carbide) is said to behave differently.
But as Master whats-his-name earlier in this thread says, for all practical reasons sharpening happens on the middle stone.

[SUN TIGER 800 grit compared to finely graded SG]

Thy Will Be Done,

I wrote to them and asked their customer service. That´s what they came back with: Tormek stones are JIS rated.

Their reply was unmistakable, I have no doubt that is true.

The #800 and #4000 Matsunaga (Sun Tiger) stone are genuinely Japanese, and have labels in original language on them. I have serious doubts that they label in FEPA.

SUN TIGER 800 grit compared to finely graded SG
Note that Japanese grit JIS #800 corresponds to US ANSI #600, and European FEPA #1200, i.e. is somewhat finer than 'finely' graded Tormek #1000.

If you refer to the above document: Wootz unfortunately got the numbers twisted.
JIS #800 = ANSI #400-500 and FEPA #360-400. (Conversion Chart Grit Sizes)

Another chart (Beware! They have many numbers wrong too)

The chart I have attached (it does not show the origin so I cannot quote) clearly reveals that a JIS#800 can be compared to a P#1200 which is a paper gauge. This is what Wootz misread.

A F#4000 stone would correspond to JIS#16.000 (according to the questionable source above), which would be ridiculously fine. It is also not logical that they term the stone "Japanese" and gauge it in some western grit unit.

[Arato]

There is one thing that I did not see mentioned yet. At least not in this context.

Japanese sharpeners almost unanimously quote the following grit ranges:

Arato (Rough Grit) has a rough surface. An Arato is useful for repairing chips, fixing a broken tip, and making an angle for a sharp blade.
Nakato (Medium Rough Grit). Sharpening with Nakato makes blade more sharp and good shape (angle) for sharp blade.
Shiageto (Fine Grit) is used for finishing the process. This work is necessary for keeping a sharp blade.

This translates into the following grit numbers:

• rough grit: < 400 JIS ≡ ca. F240
• medium rough grit: 800-2000 JIS ≡ ca. F360 bis F600
• fine grit: > 3000 JIS ≡ F1000

(Note that according to Dictum in Germany Tormek stones are gauged in JIS, which makes sense since they are selling several stones of genuine Japanese origin.)

The above link has a couple of videos where Great Master Nagao (President of Hiromoto Company) says, that 95% of the sharpening happens on the middle stone, and that any further refining is reserved for specialists.

This clearly unveils that the Tormek standard stone is too coarse for sharpening. If falls under the Arato range and no amount of dressing it will change this.

I have been in contact with two local manufacturers of stone wheels who do custom jobs, and they state that there is no such thing as making the grit finer. The grit stays as coarse as it is, but the peaks are shaved off. (Note that this only works as long as the grain is softer than the one of the dressing stone. It will not work with SiC wheels, since the dressing stone is SiC too.)

Dressing works to an extent, but there is the danger that with heavy dressing the stone untrues and that rough spots are breaking out I was told.

Theoretically the #800 grit Matsunaga stone would be ideal from the grit range perspective, but it is not since it is optimized for sharpening carbon steel plus it is very soft and quickly reacts to pressure. I personally do not get on with those stones.

On the other hand, Dictum sells a #1000 Japanese stone, which has no Tormek complement, but this is hard bond so it is better used for polishing purposes. I have a honing stone from a big Japanese maker #1000 grit medium soft, but this behaves much different and truly falls into the Nakato range.

One after market seller tells me has a #600 JIS SiC stone custom made that works for all steels and that he never dresses it. The amount of "grip" is regulated by the pressure.

So besides all the valid things that have been mentioned in the links further up, this may be another thing to be kept in mind.

I have the suspicion that (like the case with the SiC wheel) the type of bonding of the grain plays a huge role and modulates the required pressure/the amount removed.

Keep in mind that the above quoted grit ranges stem from Japanese, who traditionally use soft stones that wear quickly but remove a lot of material. Similar attention upon assessing the grit (yet towards the hard bonded end) may apply when using diamond or boron wheels.

I use the SG for setting bevels. For badly damaged chisels I use an even coarser grit.
I once had a very delicate, very thin high quality short chopping knife that went hollow no matter what I tried. I ended up sharpening it on the face of the stone. Next time I try the hard #1000 stone.

Dutchman, thank you for your kind words. I much appreciate your work too, which is the basis for many programs to follow.

Until recently I did not know any of those terms myself, as I said above, I used to look at a drill as most do: nothing noteworthy.

But when you you set out for something new, you have to dig in deeper, and now I know many of those buzz words...

(...)your knowledge of the subject is apparently of great interest to those members of this forum.

I didn´t notice

Many of these terms are explained here. You have to flip open the Drill Bit - POINT window.

The vintage book The Use and Care of Twist Drills : Cleveland Twist Drill Co shows on p.21 a nice illustration of a (conventional) split point. Sometimes those vintage illustrations are better than a photograph. (By the way, it is surprising how little has changed in the decades since this book has been printed...)

For SPA´s, you may want to glimpse at an earlier thread I started: More on Secondary Point Angles (SPA). It is all there, links and everything. No reason to re-invent the wheel.

For more links on four&more facets, Gadgetbuilder and Mazoff look at 6-facet SPA style or 6-facet tertiary relief style?

This is the quickest way, since those threads are full to burst of exactly those subjects.
Note that I have added a paragraph in the end, which I had forgotten.
Hope that helped.

[different environment parameters!]

Most hobbyists like me (until recently) don´t view a drill (drill bit as the American call it) as something special. But this is not the case. There is a lot of brainpower behind it.
After looking into this matter deeply, I no longer view drilling as a simple task, but rather as an art form. To be able to quickly apply the optimum grind to a given task is certainly the supreme discipline, but this assumes a firm understanding of the subject. So even the latter alone is empowering.

I write all this down in the hope that it may speed up somebody´s learning curve and that It may serve as a thought provoking impulse for further investigation. 
The following reflects the apex of my insights and investigations on the subject up till now and is by no means claimed to be universally valid or true or free of errors.

---------------

Grinding  Four-facet (hereafter: 4F) drill points has the undeniable benefit of being within the realm of the home sharpener since the introduction of Tormek´s drill sharpening jig;  and while this grind may alleviate some problems, it is not the end of all those problems, although the impression is fostered.

With 4F the chisel, the non-productive area at the center where the web resides is reduced by half, but it still exists and it is the cause of wear, heat generation and drill walking (although reduced).

Mazoff is a famous promoter of the 4F grind, and so is (naturally) Tormek.
Both report similar increases in service life, but neither of them reveals the surrounding parameters.

As briefly hinted above, the weak point (literally) of the 4F grind is the region around the web. Like the standard conical point (SCP hereafter) it does not cut – it extrudes, although it is smaller than on a standard conical grind. Indeed I looked at a freshly ground small drill (6mm) with the enlargement glass after a drill session and noticed the cold-weld bead on the point coming from extrusion... This region is naturally marred first.

Both of those grinds´ center regions will run hot eventually. Now this is poison for trying to cut stainless steel. Before you realize it, hard alloy components from your drill metal migrate to the parent metal, and the piece of stainless steel turns out harder than your drill is. It will run blue and even the best and freshly 4F ground drill can fail within seconds, making it a candiate for the bin.

It would seem that a cutting point like a conventional split point (hereafter: CPS) would eliminate that problem, and to an extent it does, but the downside is, that this faces you with yet another grinding challenge.

Honorable members of the scene like ,,Gadgetbuilder" John Moran think, that CSPs or similar measures are only necessary for bigger drills (say from 12 mm upwards), while he thinks that small drills perfectly get along using a 4F point.

But there is a different, equally valid approach that came to my ears:

My brother-in-law works in a factory making balconies and fences out of aluminium and stainless steel (wooden balconies being almost extinct). They use small drills like 3.1mm (for some reason)  for pre-drilling, and those do employ a CSP grind. They swear by them. Those bite into the parent metal more readily and thus reduce the risk of burning. They also have a limited tendency to walk. None of the drills they use hereafter are split. They don´t see the purpose for splitting them.

Moran again, in total contrast, advocates the use of a small drill (like 5mm) ground with 4F for pilot drilling. To be precise, he prefers spotting drills (ground to a very flat angle) over center drills to eliminate chatter and walking. Link.

So what is going on here? The answer is: different environment parameters! The prior clientele mainly uses drill presses and hand drills, the latter speaks of lathes resp. NC machinery (where Moran comes from) that have a very tight grip on both parent material and drill.

Furthermore, Mazoff in his well-known article tells us that his modified split point (hereafter: MSP) yielded much bigger service life than other´s, which will be true beyond doubt, but what did they use it for? Cast iron cylinder heads? Those are notoriously bad to drill even with pilot holes I heard.

We cannot view the performance of a drill (or rather a drill´s point geometry) isolated from neither the parent material nor the machinery.
The logical conclusion to this is that none of the grinds provides the final answer to all cases. Nor can the service life be attached to a certain grind indiscriminately.

Before I came to all those conclusions, I tried to apply my artistry to the Tormek. I modified the jig somewhat and managed to successfully grind something probably akin to Mazoff´s MSP (after many failures...). I can elaborate on this if there is a demand.

This can be applied to 4F (although with the relief facet only ground to where the corner meets the web rather than up to the center) and store-bought SCP´s. They work well into virgin parent metal, but apparently no better than using a pilot hole with a stock SCP.

That all said (and John Moran has come to the same conclusion eventually) you may instead want to equip bigger drills with secondary point angles (SPA, see Mazoff). I find that those much reduce the tendency of drills to block upon break-through on the bottom side of the parent metal.

SPA´s can be realized easily and faithfully on the DBS-22 with a slight modification of the sled (shown elsewhere here). Being cutting edges, they eventually need relief, but not if you keep it decent. John Moran told me this upon a private contact.

So the upshot is, for a hobbyist sharpening with a Tormek (and this unit is no doubt geared towards the advanced hobbyist), particularly if you mainly drill mild steel or stainless by hand (or drill press), you do not desperately need to equip big drills with a CSP (or similar), but you may want to invest into a pack of high quality drills with a split of sorts for piloting (you cannot grind a split point onto small drills with the Tormek). While you are in the shop, you may also get a specimen of a precision center punch.

Alternatively, a 4F small drill (such as 5mm) may serve well for this purpose too.
(Note that Moran grinds smaller drills without relief facet and that very small drills cannot be ground at all on the Tormek without additional gadgetry).
You may want to consider applying SPA´s to bigger drills, such as from 10 mm upwards.

Note that Mazoff goes on at length that that the influence of point angles and relief angles on the result may have a much greater impact on the performance than the point geometry itself. I recommend studying his essay ,,Drill Point Geometry" in depth.

Non-iron material must be investigated separately, and to my knowledge no mention has been made as to the relevance of 4F to those. That said, I have read that SPA´s are known to be beneficial particularly on plastics and thin sheet material.

One thing that has not been touched upon yet is the general aspiration level concerning drills. A company may have as one of their goals that a maximum number of drill operations per time slot are completed. Mazoff obviously comes from that corner, he clearly speaks for large scale manufaction where every second translates into money. So the necessity for pre-drilling may mean a loss of time that cannot be disregarded. On the other hand, a manufacturer of drill bits themselves may skip any web thinning action in favor of shorter (read: cheaper) time-to-market.

Again for the hobbyist (particularly of the model maker type), I guess quality may be the main aspiration, but I know many car tinkerers that could care less about precision and just want a hole done, period.

This is another perspective, from which we may have to view the discussion.

Edit:
Another facet of the subject (pun intended) might be worth considering: the experiments quoted by Mazoff and Uddeholm are no doubt executed under controlled environment conditions. In practical terms this means for example: a rigid drill press or similar, controlled feed, controlled speed, controlled thrust, controlled cooling and lubrication, a certain type of material and probably more. The kind reader will immediately recognize that none of that can be met by a layman. I leave it up to you to decide how meaningful such tests can be for practise.

Not sure it would help if there is significant play between the parts

I don´t think it would help. It is not so that the axle is bent or the fastening screw´s flange non precise...

I think part of the problem is axial play on the stone. Even a tenth of a millimeter play will be transported to the circumference and appear as wobble both ways. The above mentioned cheap stone it was originally fitted with some disgrace of an adaptor. Wobble was a nightmare. I was surprised how well this now behaves after fitting it with a tailor made adaptor and truing with the diamond.

I think the other part is the mounting flange and/or the blotter:

Blotters help to assure that the flange clamping pressure is evenly distributed on the wheel. (...) You must therefore use one clean new blotter for each mounting flange.(...)
Never re-use old blotters when remounting wheels.

(Source: Blotter size vs. Flange size - what is the Rule? by Nortonabrasives.

While this surely applies to fast running wheels, it will be applicable to an extent even to our situation. Because nothing else can explain why re-opening and re-fastening cures the problem. (sometimes.)

[the problem is that you true any wheel and the next time you mount it it wobbles.]

For me, the ,,woodworking" machines are a specialized compromise. They can do everything, but are not particularly excellent in any field. Do not misunderstand what I'm saying.

Let´s take Dan´s case. 10 knifes per week can already be considered volume sharpening, in the sense that permanent swapping of wheels and that quickly explodes into excessive additional load.

A dedicated sharpening service would never put up with such fandango, they would go and buy dedicated machinery for each task.

Yet being an advanced hobbyist, considering you had such (even small) volumes of drills, knifes, chisels etc. to sharpen, you would immediately go and try to limit such procedures as swapping wheels, even swapping USB etc. by obtaining more machines for the individual tasks. Even if it were just a wet/dry grinder like Dan uses.

Our Wootz went an intermediate way by buying a Tormek for each task: stone1, stone2, leather strop (methinks), felt wheel, and a  half speed large axle (fast) grinder for the paper wheels.
The earlier ones work well whith the given axle length, the latter are specialized anyways.
And that is only the knives served...

There is a line beyond which you want to determine which way to go.

I do a lot of experimentation, like the recent face grinding for secondary bevels (relief), so I have a very coarse wheel, the stock wheel, a SiC wheel and a polishing wheel. Those cover the grit range from 120,220,600 to 1000 for individual tasks. Sometimes you need two wheels at least for a knife or axe. Ramming my basement full with individual machines? No. Too much space, too costly.
And let´s face it: we probably have all started out wanting sharp knives. Do we want to be slaves to all that gear?

Yes I can see the point, and yes it gets up my nose too, but I am content with it. I have thought about dedicating my wet/dry grinder to the felt wheel. That´s about it.

So because it has been asked here what the problems are with changing wheels: the problem is that you true any wheel and the next time you mount it it wobbles.
I find myself re-opening and re-fastening the wheels several times before it runs acceptable, but never as true as before.

The SG-200 (I have a T3), unlike the after-market other wheels I have, has a few tenth of a millimeter bore play and I have to put on thin layers of adhesive tape every time I mount it. And of course remove this once I use a different wheel.
This is really sickening.

If anybody has found a fix for this, I would be very thankful.

Oh and by the way, the coarse wheel is the re-purposed wheel from said wet/dry grinder. It has a 20mm bore and came with an entirely useless adaptor.
I had one 3d-printed with a bore that fits very snugly. Once trued, it is much easier to get mounted and run true.

May I suggest you look at the video on the knifegrinders site concerning deburring. This tells you a lot on removing the burr. I bought a felt wheel according to the specs given there and that works much better for me than the strop wheel. Well, to be fair, it is a slightly different field of application. BUT, once you remount it you'll have a hard time to get it running true again... it is Semi-rigid.

[cbwx34]

There she goes.

A lookup table to set up a honing rod according to the method outlined by cbwx34. All you need is a fine permanent marker.

There is some caveats:

• this method is independent of the blade height, the excess back portion of the blade just protrudes past the rim. But on the contrary, a given setup may not work for very slim knives
• you may have a square rim (i.e. finger protection on the corner of the handle). Choose the smaller one (the bigger one quickly yields distance values only suitable for very big knives)
• you may have an oval rod. choose a suitable side. Usually the finger protection flanges protrude to the wider side.
• First tests revealed that it is quite uncomfortable to look at the markings. You better remember, how much your knife sticks out beyond the rim on the top (a further improvement by making a physical stop there comes to mind

This method is no worse than the one outlined by me initially, but only needs a one-time setup. (Maybe an occational touch-up is needed).
Please can somebody verify the calculations.

[cbwx34]

Ha, that´s a brilliant approach from a different side. You vary a different parameter of the right angle triangle.

In seeing your pictures I realize that all of the above contemplations, my idea foremost, are dramatically simplified:

• the basis of those calculations is a triangle. In real life, it is a segment of a circle with the pivot point being the point of contact knife/honing rod
• the width of the "wedge", i.e. the width of the blade, is not being accounted for.

The error was considered small, but seeing how close the marking lines on the rod are and how easy it is to miss them, lead me to the following conlusions:

• the method of using a hone rod is proven working over several decades
• the operation is probably mostly executed by personnel in ignorance of the underlying principles
• maintaining a precise angle throughout the action must be uncritical
• the whole process must be uncritical
• the process must be simple enough to be executed by personnel not knowing the theory behind it
• the process must be simple enough to be applied to every hone specimen
• the calculation must be simplified enough to exclude the need to use specialised equipment (3D printer, PC etc.)

What further supports those observations is, that ideally the honing rod should not remove any material, which is why the mostly revered rods have a "diamond" or "micro-mesh" finish, or none at all. All ceramic rods I have seen fall into this category (besides the fact that a very hard steel very likely needs something harder than itself to rub against...) It (ideally) does therefore not grind a new bevel but re-erects the cutting lip. In consequence, it does not help if the knife is genuinely blunt.

So, back to cbwx34´s method:

I prefer your method over mine, because it excludes the factor "blade height". Furthermore, the reference point is further down the knife´s face where blade with is smaller and the error introduced by ignoring the blade with too.

Seeing how close the 15° and 17° lines are and how questionable it is that somebody can maintain that exact angle, it appears that two lines (15° and 20°) drawn all around the circumference are probably enough. How do you find that folks?

I will later on the day make an extension to above spreadsheet that lets you input your hone´s collar width and calculates the distances for you.

I dare to disagree. This is a new wheel. It is a real improvement to get the Ma'm understanding the merits of using a hone and how.
But keeping a stash of them cones is asked for too much IMHO.
In real life, the average kitchen has ONE knife that is used everyday, so, agreed, one cone is enough.
For the advanced cook the multi-cone is a god send. Ahem right after the lookup table of course🤣

But thinking about reduction for the sake of practical simplicity a 15-17.5-20 cone with 3 dedicated flat symmetrical reference planes is ample.
This is no way about .1 of a degree...
And those who have a 12 dps knife made of unobtainium probably don't need to worry about edge retention too much...

It will be a while until I see my buddy again who has some machines like that, but I most certainly have some made for me and my family members whom I trained tu use such a rod.

This is quite self-indulgent since it is their cutlery that lands on my doorstep🤣

Cudos for the Idea!

I'll report back on my experience.

Sir Amwell,

I suspect that freehanding comes with time.
For the moment, I am glad I can get my cutting tools sharp with the crutches. There is enough to comprehend to get it right first hand.

Whoa, that´s something! That´s the housewife´s nirvana!
It cannot be simpler.

For the bore, this would need to be adapted to different rod diameters.
May I suggest, the indicating notch should point towards you (if it doesn´t already), while the reference angle is 90° sideways.
And the numbers, so they are not obstructed by a flange that may be there, should be operator readable, i.e. 180° rotated.

But this is complaining on a very high level
congrats.

I tend to do a batch of all my own kitchen knives maybe 10 or so at a time once a week(ish) and I do not want to take the wheel off and then put it back on for each knife. Hence the honing apart on a separate wheel/machine without any obstacles at all!

I can just grind then hone quickly without any faffing around or changing any set up.

Dan,
I just recently pondered about similar things.
This disk-swapping is a nuisance. I could live with it, but the real drag is that once you have your wheel beautifully dressed and running true, it´s all up the Swanee once you re-mount it again.

I use the leather wheel for honing, but I also use the rock hard felt wheel afterwards. IMHO the prior polishes the bevel, the latter gives it the real sharp edge.

Those machines you have are actually very cheap (particularly used), and as a matter of fact, they look absolutely identical over here. Probably all from the same Chinese factory.

One could get them used for next to nuthin´ and set one up for stropping and one for deburring, but then... There gotta be a stop to this.
I also use several wheels (a coarse for heavy jobs, a medium for the meat, a fine for polishing and one for the hard stuff), and you´d probably want separate machines for them. But indeed, the pro´s do have separate machines for each task...

Where is the end? I leave it as is and live with it.