Angle Suggestions For Two Knives

[Kekoa]

So I just got some angle guides in the mail and I'm itching to get my two J knives bevels set the way I want. I am looking for some suggestions on what angles would be best.

The first knife is my Yahiko G3 Santoku. I have another topic about some of the micro chipping problems I have been having and I'm looking to make the bevel just a little more robust. It seems to be currently somewhere between 12 and 14 degrees from what I can tell. Where do you think I should go from there if I'm looking to get a little better edge stability?

The second knife is my Yoshimitsu W1 Fugen Gyuto. It had a pretty sloppy OOTB grind that was a bit uneven, and I just want to get it cleaned up with the edge set at an appropriate angle. This knife is definitely more robust in geometry so I imagine it might actually be able to handle a steeper edge angle better, but I wanted some advice from those with more experience. I am not in need of anything super steep, but if it can handle it, I wouldn't mind going steeper than it is now.

What would you suggest?

[ex1580]

I have some of those blue angle guides. I don't use them a ton because I find it get's me into trouble spending a lot of time screwing around with angles and it's a pain to keep them from scratching the face of the knife (use blue tape). Most of the knives I buy the sharpener probably knew what they were doing enough to have the angle correct so I don't mess with it, but I have and learned this the hard way, and if it's someone else's knife you never know.

When I do use the guides I use the 10 degree angle for the Japanese knives (a very general statement), the 13 degree for modern western edges, and the 20 for my vegetable clever. This is very generic and there are a lot of knives that fall between that I just "feel it out". I use the 75 minus the RHC as a rough estimate as to what the steel can take and make sure I am not pushing it too far. I never dip below this number. This leads me to...

Remember that you are measuring the blade angle from the center line of the knife so if you are using the blue wedges you would need to know the blade angle (the angle at the apex between the center line of the knife and the face) first and add that to the guide angle. This is because the blue plastic wedge contacts the side of the blade to add to whatever angle is there. I usually do this using an angle cube and a flat surface. Zero the cube, hold the knife down and measure the angle, divide by two.

You will just have to play around with it a little. If the knife chips then try a micro bevel where when you are done on your finishing stone you do a couple of strokes (literally one or two per side) at about five degrees more than you sharpened at on that same finishing stone. Usually takes care of it.

Good luck and happy sharpening!

[Kekoa]

Well I'm trying a roughly 15 dps for my Santoku, which isn't super exact by any stretch with my freehanding but it will give me a baseline reference. I'll try that angle for a bit and see how it turns out. Just tried it out on carrots and it cuts well, just have to wait and see how durable it is.

For my Yoshimutsu I'm thinking maybe I'll try 14 dps and go from there.

[Jeff B]

...I use the 75 minus the RHC as a rough estimate as to what the steel can take and make sure I am not pushing it too far. I never dip below this number. ...

Don't know where you came up with this but it sounds ass backwards to me. You're saying the harder the steel the lower the angle it can take when it's the higher HRC that can make a steel more brittle. If I'm understanding this correctly you're saying a steel at 61 Hrc should not go below 75-61=14 degrees. That same steel at 65 Hrc should not go below 75-65=10 degrees. Not logical at all.

...Remember that you are measuring the blade angle from the center line of the knife so if you are using the blue wedges you would need to know the blade angle (the angle at the apex between the center line of the knife and the face) first and add that to the guide angle. This is because the blue plastic wedge contacts the side of the blade to add to whatever angle is there. I usually do this using an angle cube and a flat surface. Zero the cube, hold the knife down and measure the angle, divide by two...

And this...WAY over thinking and over complicating things.

I'm really not trying to be rude about this but those were my thoughts when reading that post.

[ex1580]

Sorry, Jeff, I read it here on this forum and should have given them credit. It's funny though that I try to over simplify the angle and yet make calculating it so hard because math is fun, haha.

I use the 75 - RHC trick as a rough guide and interesting amusement. It actually does line up nicely with most of my knives, but not all. If a knife is really soft and I go with a small angle like 10 degrees then it doesn't seem to hold an edge (low edge retention on the board, but it depends on what you are using the knife for I guess) but if a knife is really hard then it chips at a low angle. When I look at the outliers on my chart there are some such as AS steel that often come in a little below that calculation that I watch closely for chips (none so far, but if ground thin it feels delicate), and Wüsthof which ships with a 14 degree bevel that the calculation says should be 17 (but I am sure those Germans carefully calculated the Vanadium content). Of course when you start looking into what makes a steel wear resistant or tough then it gets all kinds of wild and the information about the steel makeup can be hard to find and good luck with the heat treatment.

Soooo, maybe I was a little strong on that statement about the calculation but it's a neat starting place and surprising how many knives arrive and/or work really well within one or two of that number if you can calculate it. But for the OP, I normally use the 10, 13, or 20 degree angle guides if I use them, and I measure and write down everything I can first.

EDIT: Just FYI the rudeness meter is turned off for Jeff B.

[Jeff B]

Thanks for the added information. It's funny as long as I have been around here that I've never heard of this and somehow don't remember ever seeing that thread. I'm also surprised that it was Grant that posted that because I highly respect his overall knowledge. I'm also very familiar with TallDark&Swarthy(Rick) from the old forum that he credits for coming up with this, he was also a very knowledgeable and respected member. They make a good argument in a linear way for this formula but it still doesn't impress me for whatever reason. I guess I just don't agree with the calculation results as I explained above and would need more of an explanation of how this formula came about to bring me around to it.

[ex1580]

I cant find it at the moment but I recall reading somewhere that one of them was trying to simplify finding a good knife angle and had a bunch of data about steels they had sharpened and angles they used. I believe they just made the calculation up because it worked, at least close enough, to how they were sharpening at the time. Of course that was a little while ago and things may have changed.

[jmcnelly85]

For the time being, I think finding a single angle for each knife will help the overall sharpening process. Keep building muscle memory and confidence, worrying about a 1 degree difference between two knives sharpened freehand will not get you closer to being a better sharpener. Sharpening the two knives enough times will get you closer to being able to read and tell your knifes abilities and limitations. For the time being, keep things as simple as possible, keep building a foundation of muscle memory and learn to read what your knife is telling you on the stones and on the board.

[Jeff B]

For the time being, I think finding a single angle for each knife will help the overall sharpening process. Keep building muscle memory and confidence, worrying about a 1 degree difference between two knives sharpened freehand will not get you closer to being a better sharpener. Sharpening the two knives enough times will get you closer to being able to read and tell your knifes abilities and limitations. For the time being, keep things as simple as possible, keep building a foundation of muscle memory and learn to read what your knife is telling you on the stones and on the board.

Ah...the ol' KSS formula, Now that I can get behind!

[David_R]

Thanks for the added information. It's funny as long as I have been around here that I've never heard of this and somehow don't remember ever seeing that thread. I'm also surprised that it was Grant that posted that because I highly respect his overall knowledge. I'm also very familiar with TallDark&Swarthy(Rick) from the old forum that he credits for coming up with this, he was also a very knowledgeable and respected member. They make a good argument in a linear way for this formula but it still doesn't impress me for whatever reason. I guess I just don't agree with the calculation results as I explained above and would need more of an explanation of how this formula came about to bring me around to it.

This seems odd to me as well. HRC is generally not a factor for me choosing a blade angle except with softer stees. Intended usage of the knife is more important to me. I can sort-of see the reasoning: the softer steels like Victorinox uses won't support a smaller angle, but this doesn't work as you get into harder steels. This formula would put a 66 HRC knife at 9 degrees.

[Radar53]

Thanks for the added information. It's funny as long as I have been around here that I've never heard of this and somehow don't remember ever seeing that thread. I'm also surprised that it was Grant that posted that because I highly respect his overall knowledge. I'm also very familiar with TallDark&Swarthy(Rick) from the old forum that he credits for coming up with this, he was also a very knowledgeable and respected member. They make a good argument in a linear way for this formula but it still doesn't impress me for whatever reason. I guess I just don't agree with the calculation results as I explained above and would need more of an explanation of how this formula came about to bring me around to it.

Jeff you are correct, I got this from Rick and always credit him when I post it. For me it's just one of those "rules of thumb" to get you into the ballpark. I think that for new sharpeners deciding on an angle to set on an edge, is always a bit of an unknown. Yes, as always there are a multitude of other things to take into consideration, which can be factored in as people gain more experience. For me, the formula just provides something of a starting point. For example, my Shibata's (RHC 61) are at angles way lower than the formula would suggest and my Kohetsu HAP40 (RHC 65), knives are at a higher angle than the formula suggests.

[karnaknives]

Anywhere between 10 and 15 degrees per side would be appropriate for most Japanese knives.
For my personal knives I keep them at about 12 degrees per side.

As far as the blue wedges, I have only ever used them as a training guide - I set the wedge on the stone, and set the knife on the wedge, and hold the blade AS IF I were sharpening to let my hands feel the angle, and my eyes see the angle. I would move the blade away from the stone and then while still holding the blade, place it back on the stone and check my angle against the blue wedge.
You could do the same thing while sharpening - you could "set" the angle using the wedge, and then make a few strokes across the stone, leaving the wedge behind, and then stop and check your hand and blade position using the angle.
It's just something I used to do frequently to build that visual and muscle memory into my eyes and hands to achieve certain angles.

I have not ever tried sharpening the blade while attached to the blue wedges or moving with the blue wedge in any way and I don't know how well that would work.

[polytope]

^^ this is how I use the wedges too. I use them at both the near and far edges of the stone, especially when working on curved sections because I have less practice with elbow-raised arm positions. I've also settled on 12 degrees for Hitachi steel, 18 for German.

If you use them this way, my tip is to put them on the stone upside-down, with the writing against the stone and open side facing up, because the open side is less "sticky" when wet.

[ex1580]

If you use them this way, my tip is to put them on the stone upside-down, with the writing against the stone and open side facing up, because the open side is less "sticky" when wet.

This is a great idea! Much better than using a rubber band.

[Kekoa]

Anywhere between 10 and 15 degrees per side would be appropriate for most Japanese knives.
For my personal knives I keep them at about 12 degrees per side.

As far as the blue wedges, I have only ever used them as a training guide - I set the wedge on the stone, and set the knife on the wedge, and hold the blade AS IF I were sharpening to let my hands feel the angle, and my eyes see the angle. I would move the blade away from the stone and then while still holding the blade, place it back on the stone and check my angle against the blue wedge.
You could do the same thing while sharpening - you could "set" the angle using the wedge, and then make a few strokes across the stone, leaving the wedge behind, and then stop and check your hand and blade position using the angle.
It's just something I used to do frequently to build that visual and muscle memory into my eyes and hands to achieve certain angles.

I have not ever tried sharpening the blade while attached to the blue wedges or moving with the blue wedge in any way and I don't know how well that would work.

This is exactly the technique I ended up using. Because I have no previous experience determining the angel I'm at, I just use the wedge as a reference before I make my sharpening stroke, then I check my angle every once in a while.

[ex1580]

For whatever it's worth if anyone was curious about some official instructions please see here: https://www.wedgek.com/