I have had my business up and running for just over 2 months now and although its doing quite well, I have a question for the forum that I know docent have a absolute answer but I will ask it anyway for guidance. I get a lot of knives that are in bad shape and although I have been looking up the website of the knife maker or Googling the answer, I try to put the factory recommended angle on it or a default 18° and was wondering if anyone who sharpens for the public chooses a different angle?
In all honesty, I would like to have a more "standard" angle to sharpen customers knives except for very specific knives that require a specific angle (As an ex chef, I use Japanese knives and sharpen most of them at 15° and have some as low as 12°) and I am wondering if the standard 18° should be lower, possibly 15°? I understand that this may leave less material behind the edge and most cheap knives wont stay sharp for long so is there a compromise edge angle? Any input would be most welcome.
I am not a professional so take my advice as it comes. My approach is to select a default of 20. The reason is two fold. First, the majority of general purpose kitchen knives recommend that angle, and second it is a good angle for general purpose use whilst not making it too fragile. I would have thought that 18 would also be a good compromise. When I do use a smaller angle I advise the owner to reserve that knife for fine work et al to prevent damaging the knife. All of my sharpening is for home use by non professionals so I rarely use a smaller angle.
I used to sharpen @20dps a long time ago. Then I came across Wootz's litterature and decided to give 15dps a try.
It has been my standard since. I made comparisons using the same knife model sharpened at 20 dps and 15dps, the 20 dps got dull significantly faster. I have not noticed 15dps being too fragile for standard to fairly high quality knives.
15 degrees/side unless a customer asks for something specific (they very rarely do).
Considering almost every knife handed to me by customers are at the tail end of trying almost every other gadget and sharpening service prior, there's never any sharpening angle to duplicate.
Kitchen knives: 15 DPS
Cleavers: 17 DPS
Fancy Japanese knives: 12-15 DPS
General use and fabric scissors: 60 DPS
I typically measure the behind edge thickness (knives only) and aim for a secondary bevel height between 1-2mm.
So far this framework seems to balance a smooth flow from the secondary to primary bevels, as well as edge retention for at least a few months for average 55-58 HRC steel.
Quote from: tgbto on June 01, 2026, 09:32:40 AMI used to sharpen @20dps a long time ago. Then I came across Wootz's litterature and decided to give 15dps a try.
It has been my standard since. I made comparisons using the same knife model sharpened at 20 dps and 15dps, the 20 dps got dull significantly faster. I have not noticed 15dps being too fragile for standard to fairly high quality knives.
So do you feel your customers knives keep their sharpness long enough to their satisfaction?
Quote from: tgbto on June 01, 2026, 09:32:40 AMI used to sharpen @20dps a long time ago. Then I came across Wootz's litterature and decided to give 15dps a try.
It has been my standard since. I made comparisons using the same knife model sharpened at 20 dps and 15dps, the 20 dps got dull significantly faster. I have not noticed 15dps being too fragile for standard to fairly high quality knives.
That's interesting, I am currently doing some tests between 18�° 16° to see how long the knife edge lasts. My main concern is that the knife stays sharp for a decent period of time (a couple of months with daily use) value for money is my goal as I want the customers to keep coming back and feel they got their moneys worth.
For my customers I do 15dps. No one knows the difference between 15 and 20 and the edge lasts longer for them.
Quote from: John_B on June 01, 2026, 10:33:25 PMFor my customers I do 15dps. No one knows the difference between 15 and 20 and the edge lasts longer for them.
Thanks
When I was developing the kenjig, I wanted to standardize on a single bevel angle. The kenjig was designed primarily for sharpening everyday kitchen knives. I asked Stig to suggest an angle. He suggested 15° (degrees per side). While I have occasionally experimented with 12°, based on Wootz' recommendation, 15° has remained my go to setting.
As an update, with the advent of the KS-123, I no longer use the kenjig. In my opinion, the kenjig was a sound idea. I feel the same way about the various apps. I just believe that the KS-123 is an improvement, whether we choose to vary angles or stick with our "go to" standards.
Ken
Quote from: Ken S on June 02, 2026, 03:21:30 AMWhile I have occasionally experimented with 12°, based on Wootz' recommendation, 15° has remained my go to setting.
Same here. 12 dps is for a very specific subset of knives : suisin inox honyaki series knives whose steel is quite robust, or some of my high hardness knives. The problem with 12dps in my opinion is that although edge retention is usually better, the apex is prone to chipping. So it's only for knives that are going to be handled carefully.
As chipping is much less of an issue at 15dps, I feel this is the good compromise with good edge retention.
As a side note, when one is not concerned with initial efficiency, I find that a 10dps primary bevel with a 15dps secondary bevel works wonders as it allows for very quick touchups afterwards.
Quote from: Ken S on June 02, 2026, 03:21:30 AM...
As an update, with the advent of the KS-123, I no longer use the kenjig. In my opinion, the kenjig was a sound idea. I feel the same way about the various apps. I just believe that the KS-123 is an improvement, whether we choose to vary angles or stick with our "go to" standards.
...
I completely agree with you, Ken. The "simple method" with the Cosine Formula has now been replaced by the KS-123, which has halted the growth of computer programs and all communication about it.
What a relief, more focus on the real work.
Quote from: Dutchman on June 02, 2026, 10:44:14 AM[...] the KS-123, which has halted the growth of computer programs and all communication about it.
What a relief, more focus on the real work.
Wow, that's a tad judgmental. There are very good apps out there, and the KS-123 has significant hysteresis. Surely there is room for people who already own vernier calipers and are fine with using apps/spreadsheets ? Why the condescension ?
Thanks everyone, I think I will start using 15° as my base going forward. The KS 123 does make it easy to set this angle and since I attend a farmers market every Saturday, I can get quite busy and looking up specific manufacturers recommended angle takes time, this will help.
Quote from: tgbto on June 02, 2026, 11:00:17 AMWow, that's a tad judgmental. There are very good apps out there, and the KS-123 has significant hysteresis. Surely there is room for people who already own vernier calipers and are fine with using apps/spreadsheets ? Why the condescension ?
That is not condescension, but admiration for all the work that went into it. However, I thought I had developed a simple method, but it grew into a competition for the most sophisticated spreadsheet. An exception was the app by cbwx34, simple and accurate.
Quote from: tgbto on June 02, 2026, 11:00:17 AMthe KS-123 has significant hysteresis
I have not noticed any.
Quote from: John Hancock Sr on June 04, 2026, 03:50:46 AMQuote from: tgbto on June 02, 2026, 11:00:17 AMthe KS-123 has significant hysteresis
I have not noticed any.
Do you mean that says, one 8th of a turn on the MicroAdjust always results in the plastic needle moving on the KS-123 ? On mine, even after some lubrication, if I move the USB down, then up, I can change the angle by almost 3/4th of a degree before the needle starts moving up again. And I can move the needle up and down by hand, the flexibility and friction will let it stay wherever I put it within one degree.
I learned a new word, "hysteresis". I have known about the effect of "thread slop" on adjusting screws for many years. I first encountered this with the depth adjusting screw of bench planes. For accurate measurement, the final step should be a slight tightening of the screw to leave some load on the threads. This situation occurs even with the adjustment wheels of high quality machinery such as metal lathes. Experienced machinists make this adjustment automatically.
The Tormek online classes mention this in passing, although they have never explained why this happens. The compensation necessity is not caused by the KS-123. It is caused by the threads of the microadjust. It is not a design defect with the microadjust; it is just the nature of the beast with adjustment screws. And, on a practical basis, it is not really a problem with Tormek sharpening, especially with good technique. Use the microadjust by lowering only for rough adjusting. Make the final, more precise adjustment only by raising it.
Ken
Quote from: Ken S on June 04, 2026, 06:39:45 PMI learned a new word, "hysteresis". I have known about the effect of "thread slop" on adjusting screws for many years. I first encountered this with the depth adjusting screw of bench planes. For accurate measurement, the final step should be a slight tightening of the screw to leave some load on the threads. This situation occurs even with the adjustment wheels of high quality machinery such as metal lathes. Experienced machinists make this adjustment automatically.
The Tormek online classes mention this in passing, although they have never explained why this happens. The compensation necessity is not caused by the KS-123. It is caused by the threads of the microadjust. It is not a design defect with the microadjust; it is just the nature of the beast with adjustment screws. And, on a practical basis, it is not really a problem with Tormek sharpening, especially with good technique. Use the microadjust by lowering only for rough adjusting. Make the final, more precise adjustment only by raising it.
Ken
I have noticed this the more I use my T8, I have gotten into the habit of making my final adjustment when raising the universal support.
To borrow a phrase from Wolfgang, making your custom of making the final adjustment by raising the microadjust will serve you well. In itself, it may not be a big deal; however, small improvements compound.
Ken
Quote from: Ken S on June 04, 2026, 10:43:54 PMTo borrow a phrase from Wolfgang, making your custom of making the final adjustment by raising the microadjust will serve you well. In itself, it may not be a big deal; however, small improvements compound.
Ken
Probably why I don't notice it. I allow for the slop in the mechanism, always have done. Force of habit.
There are two phenomena with hysteresis here :
- One linked to the threaded rods, which can be compensated by always ending with slightly raising the USB. This is standard operation and does not cause any issue. It will prevent the USB from settling lower due to the rod moving slightly insided the nut before getting fastened.
- Another one linked to friction inside the KS-123. Going down, then up, will ensure that the error is always on the same side. For a given static friction coefficient, that is, which will depend on when it was lubricated, if it is slightly wet or not, how tight the nut is, etc. Plus, the amplitude of USB movement necessary to put the needle back in motion on the way up is much, much higher than with vernier calipers resting against the top of the USB and the wheel where only the slightest turn of MicroAdjust nut is enought to lift the lower end of the wheel.
So while using the down-then-up routine will minimize the error, it will still be more important than using the distance method, less reproducible, and therefore the amount of material that needs to be removed before raising a burr will statistically increase.
When I hear concerns about using the KS-123 due to it being less than needed accuracy, I wonder why the angle on the blade must be accurate to 0.1°. In the sharpening I do for most things, if the angle is good to +/- 1 degree I am good. What am I missing?
Quote from: RichColvin on June 06, 2026, 12:10:04 AMWhen I hear concerns about using the KS-123 due to it being less than needed accuracy, I wonder why the angle on the blade must be accurate to 0.1°. In the sharpening I do for most things, if the angle is good to +/- 1 degree I am good. What am I missing?
Nothing.
I think this is an example of going to the extreme without any clear delineation of the benifit. When Wootz proposed some new idea he backed it up with extensive testing and real world usage in meat packing plants. I believe only a miniscule number of users have the ability to measure the angle to this accuracy.
My overall goal is to give a service that the customer deems necessary if they love to cook and the feedback they get from a knife sharpened by me makes them realize that I should be the one to maintain it for them. Being a professional plant based chef, I have to keep my knives in top condition as I am predominantly dealing with dense, fibrous ingredients so my Enso's are sharpened to 12° but I was not sure if most customers would notice a difference between 15°. 17° or even 20°, I have some knives that I have been doing tests on and I definitely notice a difference in angles but I have been cooking for over 40 years and quite a control freak.
It's been an eye opener hearing other sharpeners opinions on what angle they use for their customers, 15° being the norm, I just don't want customers coming back saying the knife was sharp for a couple of weeks and now not so much but I guess I can't control how they use and abuse their knives and a "one shoe fits all" approach shouldn't drive my business, It would be nice to have a "go to angle" that's sharp enough to make a difference but durable enough the last some time and allows me to maintain a decent speed so I can move through a medium to large volume of knives while maintain quality (I use two T8's, one course grit and one fine grit). Nirvana I guess.
Quote from: John_B on June 06, 2026, 01:13:00 AMQuote from: RichColvin on June 06, 2026, 12:10:04 AMWhen I hear concerns about using the KS-123 due to it being less than needed accuracy, I wonder why the angle on the blade must be accurate to 0.1°. In the sharpening I do for most things, if the angle is good to +/- 1 degree I am good. What am I missing?
Nothing.
I think this is an example of going to the extreme without any clear delineation of the benifit. When Wootz proposed some new idea he backed it up with extensive testing and real world usage in meat packing plants. I believe only a miniscule number of users have the ability to measure the angle to this accuracy.
If I may introduce a modicum of nuance and open-mindedness to "Nothing" :
- I agree being able to
measure the edge angle with 0.1° precision has no benefit in terms of sharpness or edge retention
- However, being able to
reproduce a given angle quickly with the smallest deviation possible results in raising a burr much faster, with less metal removal.
As we are talking small angles, the amount of metal being removed is proportional to the ratio of angles : you remove 5 times more metal if you're 1° off compared with .2° off. It is to me a clear delineation of the benefit. [EDIT] Actually, much more than this if you take into account cases where you will be thinning the blade [/EDIT]
And you see: "does it really matter"?
Well I think it does because as you are going through your protocols you have to TRUST in what you are doing, for consistency and peace of mind. And if you trust in the ks123 and there are variances with it then that's no trust at all.
May as well have a reference plate on a belt sander and trust to luck every time.
In the real world it may not matter, but if one is trying to achieve a particular result and testing protocols it does.
I ditched the ks123 a while back because I couldn't trust it. There or there abouts with the slop in it or whatever you call it is no good for me so went back to angle calc.
Funny old world.
As long as I follow the instructions and always start from a smaller angle when using the KS123 to approach the desired angle, I have no problem with precision. And that means that when I'm re-sharpening, I can usually feel the burr after just two passes with the CBN160! A great accessory!
Quote from: Drilon on June 13, 2026, 08:57:01 PMAs long as I follow the instructions and always start from a smaller angle when using the KS123 to approach the desired angle, I have no problem with precision.
Unfortunately that's not how friction works: once the static friction coefficient is no longer sufficient to keep the needle in place, it will switch to kinetic friction, and the needle will move as much as necessary to get back into the friction cone. Then stay in place, and here we go again. So while the error may always be on the same side, we have little control on where the needle stops.
As for a 160 grit stone raising a burr quickly, I have no doubt.
I find that ensuring that all three pins are firmly on the wheel and the bar is held as indicated in the Tormek videos I can get the angle spot on.
Quote from: John Hancock Sr on June 16, 2026, 03:54:21 AMI find that ensuring that all three pins are firmly on the wheel and the bar is held as indicated in the Tormek videos I can get the angle spot on.
John, do you measure the sharpening angle you achieve to compare it to the KS-123 setting?
I am always concerned with what new readers who have not yet acquired much background in Tormek sharpening will absorb from our posts. I would use the research our late member Wootz (Vadim of Knifegrinders Australia) did with the meat packing factories in Sydney. I admire Wootz and his work. However, like many other experienced forum members, Wootz' industrial sharpening schedule was far more intense than mine. I suspect the meat packing knives that Wootz sharpened were probably sharpened more often in a week than most of us do in a year. I expect our regular members to be aware of this. I am not certain that many of our new members and guests are aware of this.
Ken
Ken, you're right, I'll give it a shot.
TL/DR : 15 dps.
For a more detailed summary : most members recommend something in the 15-20dps range, with a majority grinding closer to 15dps. Setting this angle using the KS-123 is practical for low-volume sharpeners.
QuoteJohn, do you measure the sharpening angle you achieve to compare it to the KS-123 setting?
No, but I do not get any hysteresis, which is the discussion I am commenting on. If I wind up a fraction the needle moves, if I wind down a fraction the needle moves.
Tgbto,
I agree that the KS123 is very useful for low volume sharpening, which, I suspect, is what most of us really do.
My question is, if the KS123 is not satisfactory for high volume such as "weekend warrior" farmers market sharpeners, what is satisfactory? Remembering designing the kenjig, the two major components of sharpening were the grinding wheel and the knife set up. Any modification to either could not negatively impact the quality of the sharpening.
The kenjig is not limited to just one bevel angle. setting up for more than one angle just requires making extra jigs. This is no big deal, either is construction time or cost. It will lengthen then sharpening time somewhat.
The real time constraint is the variety in the width of knives. Wein the real world, where most customers will bring in knives of varying widths.
Ken
Quote from: Ken S on June 18, 2026, 12:18:52 PM...
The kenjig is not limited to just one bevel angle. setting up for more than one angle just requires making extra jigs. This is no big deal, either is construction time or cost. It will lengthen then sharpening time somewhat.
...
Unfortunately, the Kenjig is valuable when used with SVM jigs that have an adjustable stop. With KJ jigs, its usefulness is very limited.
My own rule of thumb: as thin as possible, but thick enough.
30 degrees inclusive (15 degrees per side) is my upper limit, if a certain steel cannot handle this angle i have no use for it.
My Cold Steel machetes in extremely tough 1055 steel @ 56 HRC have hand convex ground edges of ~30 degrees inclusive, while my Condor machetes in still very tough 1075 steel at a little higher hardness also have hand convex ground edges of between ~25 and ~30 degrees inclusive.
With quality Chef knives my aim is ~20 or ~22.5 degrees inclusive.
Cheapies i first grind just as thin, but then apply a microbevel at ~30 degrees inclusive.
I often try to go thinner until the edge fails, then enlarge the edge angle just enough so no damage occurs anymore.
The above goes for tasks a knife is made for, not for abuse by ham-handed / ignorant people.
When sharpening for others an important aspect is to judge with what sort of person you are dealing with, and also what his or her requirements are.
Dialing these two things in correctly often takes time, but especially the professional knife users often appreciate that you are willing (and able) to work with them to find the right combination of edge angle & edge finish that works best and longest for them.
Quote from: Ken S on June 18, 2026, 12:18:52 PMMy question is, if the KS123 is not satisfactory for high volume such as "weekend warrior" farmers market sharpeners, what is satisfactory?
The way I see it, a sharpener at a farmer's market will not reset the angle but rather reproduce the existing one using the sharpie method. If one wants to reset the angle to, say, manufacturer's specs then the KS-123 will do just fine but my gut feeling is it's not going to be the majority of cases.
When I'm talking about high volume sharpening, I'm thinking more of a "I want to sharpen these 10 knives @15dps". In that case, KJs, vernier calipers and a calculator/Dutchman's tables/a simple arccos+arcctan formula are a bliss.
In regards to the original post. I have sharpened for customers at 20, 17 and 15 degrees primarily. I now sharpen pretty much any decent kitchen knife to 15 degrees... They always come back to me needing sharpened. That's to say, I can't tell if one angle held up better or not.
All but the cheapest steel should be stable at 15%. Wootz or Larin showed the sharper the knife is, the longer it stays sharp. The geometry allows a sharper edge at 15°.
In the grand scheme of things, it doesn't matter. 90% of your customers won't know or care what angle they are sharpened to.