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Yes, the T1 indicates the angle in dps (degrees per side). So you are correct (see picture).

One word of caution however, the T1 is a constant angle sharpener so you will probably not sharpen the tip of the knives with the T1 if you previously sharpened them following the recommended Tormek technique on the T4. If you want to sharpen at a constant angle on the T4, you will need to pivot instead of lifting, ideally using a laser line on your stone.

Plus I realized afterwards that a serration is not a half-circle, but rather a portion of it, so the diameter can be wider than the pitch.

I measured my ceramic rod that just barely fits inside the serrations of a Wüsthof bread knife. It is 8mm in diameter.

I concur with 3D Anvil and kwakster.

The late Wootz, in his research, found that the highest edge retention comes with the lowest angle the knife can handle while not failing. Of course, an acute angle means risks of chipping with hard steels (and low resistance anyway to lateral damage on softer steels).

15dps (30° inclusive) seems to work a treat with most knives.

14mm is .55", which seems about right for most bread knives

Well my typical bread knife is akin to this one.

It has 35 serrations in less than 8.25", which is at most a .24" pitch.

On this other one, it looks like a .25" pitch at best (31 serrations in less than 8").

For both, the wheel will ride on the teeth.

Wolfgang demonstrates using the edge of the wheel with what looks like a 3-ish mm corner radius, which seems more like it. Typical triangular ceramic rods have an even higher curvature.

I hope I got that kind of basic math right, but I'll wager "R7" means a diameter of 14mm.

So for all knives with serrations spaced less than 14mm apart (which incidentally means all of my bread and frozen food knives), this wheel will grind the apex of the teeth and not the space in between the teeth.

When angling the knife, you're grinding with a slightly convex shape. It might increase the tendency to overgrind the middle of the blade.

Rick, thanks a lot for all the effort.

It seems fair to say that the SJ refines the edge but still leaves a significant burr that is afterwards removed by honing.

Joe,

The experience I have with Chromium Oxide is ... similar to yours. I used the technique prescribed by Wootz  in one of his videos, and let it sit a full week before using it. I still got that glassy finish when using it for the first time.

I can't say whether or not it hones anything but I'd concur with you : There are no traces of steel indicating that it does anything, and BESS scores are unimpressive to say the least. It's probably mostly due to poor technique on my side, but I've never gotten anything useful out of that wheel, unlike with other leather wheels coated with diamond spray. So I'll sand it clean whenever I need a new honing wheel.

Rick,

Thanks for the extensive testing and for sharing your results.

This subject of SJ and honing has been of interest to me since my first session with a SJ.

Why do you call what you do with the SJ wheel "honing", when the (300ish) BESS scores clearly indicate that there is still a burr ?

Also, do you know what the BESS scores were right after initial grinding ? Do you think you could get a quick order of magnitude of the BESS score after another grind on the *SG* wheel at the same angle ?

I know that's asking a lot, no worries if you can't. Thank you again for the time you've already devoted to this.

Nick.

Glad it helps. As for the diamond wheels, you probably want to make sure you have the need for them : to reshape the knife you'll need the DC, but common resharpening of carbide tools is more of a DF/DE job.

Even one diamond wheel will moreorless pay for a small versatile belt sander that will be more efficient for reshaping, but also for knifes with odd shapes, lawnmower blades, etc.

Hey Nico.

Your friend's knife can still be fixed...


I think wolfgang covers it in the knife repair video starting 6 minutes in. If you have diamond wheels, sharpening on the side will be easy, and it is still doable with the side of a SG stone.

If you have access to a belt sander, it will be the most efficient way to go IMO.

Good luck.

Tormek says no honing when using SJ wheel, but i'd like to go beyond 4000 grit it offers, into 1nm paste (12000 grit territory), so will either make my own or look for 3rd party.

Cheers

My experience is that deburring is needed even after polishing with the SJ stone. Else there is still a length of soft metal along the apex.

The smaller honing wheel prevents it from getting in the way when sharpening long knives. Else the handle or heel of the knife may interfere with the honing wheel.

If that's of any help to you, the "Top-of-USB to wheel" distance depends on wheel size and projection distance only. It doesn't change with the position of the MB-102.

That sounds good. Just make sure during the third step of your workflow that you find a way to account for hysteresis.

You could check if you made a good job of it by changing the setup of the KS-123, then reproduce the settings you just noted down, see if a new sharpie layer is properly removed.

Cheers,

Nick.