Sharpening angles for recent mules

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aprivetera
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Sharpening angles for recent mules

#1

Post by aprivetera »

Wanted to inquire about sharpening angles before this BenchStone arrives. Most of the mules have stayed far too sharp for my beginner status but it's really looking like time for a proper sharpening on my Mules. Specifically I have a SRS13/SUS 405, CPM Rex 76, M398 and the new AEB-L and was wondering what factory angles were and perhaps what your currently running if you'll share your secrets.

Gleaning from the forums it looks like 12° factory edge on AEB-L and 15° factory edge on M398. Anyone have
factory details for SRS13/SUS405 and CPM Rex 76? And what might you all be running now on these four if you don't mind me asking?

Thanks!
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Deadboxhero
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Re: Sharpening angles for recent mules

#2

Post by Deadboxhero »

aprivetera wrote:
Mon Apr 24, 2023 10:05 am
Wanted to inquire about sharpening angles before this BenchStone arrives. Most of the mules have stayed far too sharp for my beginner status but it's really looking like time for a proper sharpening on my Mules. Specifically I have a SRS13/SUS 405, CPM Rex 76, M398 and the new AEB-L and was wondering what factory angles were and perhaps what your currently running if you'll share your secrets.

Gleaning from the forums it looks like 12° factory edge on AEB-L and 15° factory edge on M398. Anyone have
factory details for SRS13/SUS405 and CPM Rex 76? And what might you all be running now on these four if you don't mind me asking?

Thanks!



IMHO the factory edge is irrelevant. It's just a placeholder. The first thing I do is put my edge on it.

Keep in mind, in order to find what angles work best It's not universal. It's NOT always determined by the steel properties. One has to figure out how they like to use their knife and what they use it for and what their preferences are. Some people are just using these edge completely differently from person to person. So, there is no universal angle for best performance.


What makes the mule team so fun is that you get to play with different steels and you get the tryout different things. Take that exploratory mindset with you when it comes to sharpening. Also, try different angles and different stones. You may be surprised to see what works best for you, but you may also be surprised to see it not work best for someone else.
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aprivetera
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Re: Sharpening angles for recent mules

#3

Post by aprivetera »

Thanks for the response. I definitely appreciate that point of view. Plenty of experience sharpening various hand tools with all sorts of files, grinders, stones, etc. Never really gave consideration to angles much before or had particularly nice steels like this where it seems to make a difference between 12 degrees on AEB-L or 15 degrees on M398.

Trying to understand the difference behind the steels at a deeper level other than just sharpening by feel, if that makes sense. I know Sal & Co aren't just picking numbers out of hat for these variables. At the same time I can appreciate not wanting to give out step by step details of how to make the special sauce.
VandymanG
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Re: Sharpening angles for recent mules

#4

Post by VandymanG »

aprivetera wrote:
Mon Apr 24, 2023 10:05 am
Wanted to inquire about sharpening angles before this BenchStone arrives. Most of the mules have stayed far too sharp for my beginner status but it's really looking like time for a proper sharpening on my Mules. Specifically I have a SRS13/SUS 405, CPM Rex 76, M398 and the new AEB-L and was wondering what factory angles were and perhaps what your currently running if you'll share your secrets.

Gleaning from the forums it looks like 12° factory edge on AEB-L and 15° factory edge on M398. Anyone have
factory details for SRS13/SUS405 and CPM Rex 76? And what might you all be running now on these four if you don't mind me asking?

Thanks!
Ok wow no pressure 😅 at all answering a question after a legend responds to your question. I’m pretty much a beginner at this mule Team thing also so keep that in mind.

Essentially I did what dead📦 hero suggested but only because my best sharpeners only go down to 15 degrees. So I did it by accident/default. It seems to have worked out.

I noticed that the SRS13/SUS405 I received had two different bevel angles so I picked one and it ended up performing worse so I then went with the second angle. My way of figuring out the angles isn’t precise as others but I did the sharpie test and honed it at different angles till the ink came off. I ended up going with 15 degree angle because that was the smallest I could go with my setup. It worked best for me with the sharpeners that I have but not sure it’s the best angle for what I use that knife for, kitchen only.

With the M398 mule I’ve been happy with the performance so I only strop it. Haven’t had the AEB-L mule long enough to have any info on it. If it’s at as small of an angle as you say it is then I’m going to need a new sharpener. Sigh 🥺 my wife is going to kill me.

Greg
Greg

* EDC> PM2 - S45VN & CRUWEAR, Native - CRUWEAR, Rockjumper - VG 10
Temporarily put my mule away cause I got tired of my wife saying do you really need 5 knives on you. MULE - AEB-L (keep returning to this mule cause it’s awesome)
tcarltonw
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Re: Sharpening angles for recent mules

#5

Post by tcarltonw »

aprivetera wrote:
Mon Apr 24, 2023 10:05 am
Wanted to inquire about sharpening angles before this BenchStone arrives. Most of the mules have stayed far too sharp for my beginner status but it's really looking like time for a proper sharpening on my Mules. Specifically I have a SRS13/SUS 405, CPM Rex 76, M398 and the new AEB-L and was wondering what factory angles were and perhaps what your currently running if you'll share your secrets.

Gleaning from the forums it looks like 12° factory edge on AEB-L and 15° factory edge on M398. Anyone have
factory details for SRS13/SUS405 and CPM Rex 76? And what might you all be running now on these four if you don't mind me asking?

Thanks!
I'd listen and relisten to every bit of advice TripleB had to say but to answer your question my Rex mules came varying between 17-19°(each side varied from heal to tip)
aprivetera
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Re: Sharpening angles for recent mules

#6

Post by aprivetera »

I plan to, tcarltonw. Believe me. Thank you for the CPM Rex 76 data point.

Thanks to you, too, Greg! And if she does at least you know the knife will be sharp!
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sal
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Re: Sharpening angles for recent mules

#7

Post by sal »

A 10X - 12X magnifying loupe helps one see more clearly what different angles and different grits look like.

sal
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"The Edge is a Ghost"
tm
aprivetera
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Re: Sharpening angles for recent mules

#8

Post by aprivetera »

Thanks, Sal. Ordered one of those as well with the BenchStone. Your knives are also superb at making order receipts disappear very quickly :)

Really appreciate all the help from the Mule Team!
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bob-atlatl
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Re: Sharpening angles for recent mules

#9

Post by bob-atlatl »

my older eyes like 30x for looking at edges, and built-in led lights, with blade at the right angle, really helps with detail.
this is the cheap one I use : https://www.amazon.com/gp/product/B07F39XWVH
... rule #9 ...
VandymanG
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Re: Sharpening angles for recent mules

#10

Post by VandymanG »

sal wrote:
Mon Apr 24, 2023 9:19 pm
A 10X - 12X magnifying loupe helps one see more clearly what different angles and different grits look like.

sal
--------------------------------------------------------------------------------------------------------------------------

"The Edge is a Ghost"
tm
Thanks Sal,

Any suggestions on sharping, especially on holding an angle while sharpening. I don’t seem to have triple-B’s super power of holding an angle while sharpening. My knife sharpeners are from work sharp, fits my budget, so it’s not cutting edge like some have. I have the angle set knife sharpener and benchstone knife sharpener. I prefer the bench stone but I struggled to keep the angle consistent and the guides only go to 20 degrees on it. Even with the guides I struggle.

Once again thanks,

Greg
Greg

* EDC> PM2 - S45VN & CRUWEAR, Native - CRUWEAR, Rockjumper - VG 10
Temporarily put my mule away cause I got tired of my wife saying do you really need 5 knives on you. MULE - AEB-L (keep returning to this mule cause it’s awesome)
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sal
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Re: Sharpening angles for recent mules

#11

Post by sal »

Hi Greg,

Do you have a Spyderco Sharpmaker?

sal
aprivetera
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Re: Sharpening angles for recent mules

#12

Post by aprivetera »

Just a quick update on the BenchStone arrival. Magnificent performance on a quick resharpening of SRS13/SUS405 mule. Excellent feedback from the stone and the steel was very easy to sharpen. Hoping to get a bit more time to properly polish, but pleased with the quick time and effort put in vs results achieved.
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Re: Sharpening angles for recent mules

#13

Post by Mr_Whiskerz »

I use this exact one as well, it's fantastic.

bob-atlatl wrote:
Tue Apr 25, 2023 8:01 am
my older eyes like 30x for looking at edges, and built-in led lights, with blade at the right angle, really helps with detail.
this is the cheap one I use : https://www.amazon.com/gp/product/B07F39XWVH
VandymanG
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Re: Sharpening angles for recent mules

#14

Post by VandymanG »

sal wrote:
Tue Apr 25, 2023 6:03 pm
Hi Greg,

Do you have a Spyderco Sharpmaker?

sal
Not yet but I’m looking into it,
Greg

* EDC> PM2 - S45VN & CRUWEAR, Native - CRUWEAR, Rockjumper - VG 10
Temporarily put my mule away cause I got tired of my wife saying do you really need 5 knives on you. MULE - AEB-L (keep returning to this mule cause it’s awesome)
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Re: Sharpening angles for recent mules

#15

Post by VandymanG »

VandymanG wrote:
Fri Apr 28, 2023 10:19 pm
sal wrote:
Tue Apr 25, 2023 6:03 pm
Hi Greg,

Do you have a Spyderco Sharpmaker?

sal
Not yet but I’m looking into it,
Hi Sal,

Edit - after reading about Spyderco’s start in the education area about us. I now feel obligated to buy a Sharpmaker. I did not realize the significance of the recommendation. Thank you for the advice. I look forward to buying one in the near future.

After doing research I ended up getting a double sided whetstone. I’m practicing on the cheap kitchen knives I have. You know the cheap ones you just toss in a drawer. My wife is now completing the the knife drawer is becoming dangerous😁 must be doing something right 🤪
Greg

* EDC> PM2 - S45VN & CRUWEAR, Native - CRUWEAR, Rockjumper - VG 10
Temporarily put my mule away cause I got tired of my wife saying do you really need 5 knives on you. MULE - AEB-L (keep returning to this mule cause it’s awesome)
VandymanG
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Re: Sharpening angles for recent mules

#16

Post by VandymanG »

The bevel/sharpening angles, HRC being pushed to higher hardness for the mules and other knives has really confused me.

When I first joined the Spyderco forum I came in thinking 15-17 degrees was for kitchen knives. But that seems not to be the case here. I also sharpened a lot of my pocket knives to 20 degrees. And lastly hard use knives around 22-25 degrees. Here it seems that pushing the angles narrower is the thing along with high hardness.

So that lead’s me to the other confusing part which is hardness. High hardness I was thought was for hair tree toppers and paper cutters. Also high hardness made a blade fragile/chippy for knives. Medium hardness was for EDC and a lower hardness was for bushcraft/survival knives. Lower hardness was easier to repair in the field (still believe this one) and higher hardness was not.

Oh and from what I can tell it looks like my 15V mule is at 15 degrees.????

I could go on but anyways just saying I’m now totally confused. Up is down and left is right in this New topsy turvy world 🌎
Greg

* EDC> PM2 - S45VN & CRUWEAR, Native - CRUWEAR, Rockjumper - VG 10
Temporarily put my mule away cause I got tired of my wife saying do you really need 5 knives on you. MULE - AEB-L (keep returning to this mule cause it’s awesome)
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Traditional.Sharpening
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Re: Sharpening angles for recent mules

#17

Post by Traditional.Sharpening »

If you've come here for answers then you'll likely just get more confused because many people here will likely confuse you further, not by some ill will or something like that but purely because they are quite confused themselves on many things.

That 15-17 DPS you mention is what I consider to be a very heavy duty edge. I've done a double-bit felling axe for a customer at under that edge geometry (it weighed around 4 lb or more) and had little concern for it being able to take this in use on wood. The difference is on a knife that geometry need only be very small, as in a micro bevel that is invisible.

I believe a lot of this confusion is driven by the oversimplification of knives and performance when it's truly a multi-faceted thing. Having only two bevels on a knife drives this to a degree, edge and main grind. How thick is the knife BEHIND the edge? This affects cutting ability and sharpening ease, yet many overlook this.

This also overlooks the fact that you are an individual and what you are cutting will be different as well, so it makes it difficult to design an edge that works for everyone without significant damage. Roughly 17 DPS seems to be what Spyderco designs for working to resist damage for what they consider most of their consumer base will do with a knife.

I personally would only ever go that high (or higher even) if it were a true micro bevel, which is needed to stabilize the carbides on steels which have higher carbide volumes. This is a published concept put forth by Roman Landes, who said the following applies to most all knives

"He classifed steels into three groups, type I, type II, and type III mainly based on carbide volume, 0.5-5%, 5-15%, and greater than 15% respectively. These groups needed different angles to both take and hold a high polished sharpness, 8-12, 12-20, and 20-30 degrees per side respectively. The greater the size and volume of carbide, the greater the angle required to keep the edge stable."

Please note that the above only applies really if you are taking the apex to a high level or polish. If you prefer using more coarse finished edges then you can actually work much lower than this and the edge will sort of micro-fracture in use giving a type of low-level sharpness which can almost go indefinitely as at a certain point it just mainly stops wearing.

The interesting thing here is that higher carbide is said to increase edge retention, yet these steels require an increase in apex angles in order to not see drastic edge degradation in use. This increase in apex angle also simultaneously lowers the edge retention compared to lower angles. This is why I am personally not fond of the idea of just mega-sizing the carbide.

Easy button recommendation would be to start grinding edge bevels at 10-12 (on the conservative side for high performance) and micro bevel according to the carbide volume ranges. Then you have the carbides well supported and also a very high performance knife for most all use that isn't really hard work. Simple steels can go far lower (appx. 6 dps).
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Re: Sharpening angles for recent mules

#18

Post by VandymanG »

Traditional.Sharpening wrote:
Mon Jun 12, 2023 3:05 am
If you've come here for answers then you'll likely just get more confused because many people here will likely confuse you further, not by some ill will or something like that but purely because they are quite confused themselves on many things.

That 15-17 DPS you mention is what I consider to be a very heavy duty edge. I've done a double-bit felling axe for a customer at under that edge geometry (it weighed around 4 lb or more) and had little concern for it being able to take this in use on wood. The difference is on a knife that geometry need only be very small, as in a micro bevel that is invisible.

I believe a lot of this confusion is driven by the oversimplification of knives and performance when it's truly a multi-faceted thing. Having only two bevels on a knife drives this to a degree, edge and main grind. How thick is the knife BEHIND the edge? This affects cutting ability and sharpening ease, yet many overlook this.

This also overlooks the fact that you are an individual and what you are cutting will be different as well, so it makes it difficult to design an edge that works for everyone without significant damage. Roughly 17 DPS seems to be what Spyderco designs for working to resist damage for what they consider most of their consumer base will do with a knife.

I personally would only ever go that high (or higher even) if it were a true micro bevel, which is needed to stabilize the carbides on steels which have higher carbide volumes. This is a published concept put forth by Roman Landes, who said the following applies to most all knives

"He classifed steels into three groups, type I, type II, and type III mainly based on carbide volume, 0.5-5%, 5-15%, and greater than 15% respectively. These groups needed different angles to both take and hold a high polished sharpness, 8-12, 12-20, and 20-30 degrees per side respectively. The greater the size and volume of carbide, the greater the angle required to keep the edge stable."

Please note that the above only applies really if you are taking the apex to a high level or polish. If you prefer using more coarse finished edges then you can actually work much lower than this and the edge will sort of micro-fracture in use giving a type of low-level sharpness which can almost go indefinitely as at a certain point it just mainly stops wearing.

The interesting thing here is that higher carbide is said to increase edge retention, yet these steels require an increase in apex angles in order to not see drastic edge degradation in use. This increase in apex angle also simultaneously lowers the edge retention compared to lower angles. This is why I am personally not fond of the idea of just mega-sizing the carbide.

Easy button recommendation would be to start grinding edge bevels at 10-12 (on the conservative side for high performance) and micro bevel according to the carbide volume ranges. Then you have the carbides well supported and also a very high performance knife for most all use that isn't really hard work. Simple steels can go far lower (appx. 6 dps).

Wow, thank you very much for the info. I’m very grateful that you took the time to give as much info as you did.

Once again thank you!
Greg

* EDC> PM2 - S45VN & CRUWEAR, Native - CRUWEAR, Rockjumper - VG 10
Temporarily put my mule away cause I got tired of my wife saying do you really need 5 knives on you. MULE - AEB-L (keep returning to this mule cause it’s awesome)
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Bolster
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Re: Sharpening angles for recent mules

#19

Post by Bolster »

Traditional.Sharpening wrote:
Mon Jun 12, 2023 3:05 am
...I personally would only ever go that high (or higher even) if it were a true micro bevel, which is needed to stabilize the carbides on steels which have higher carbide volumes. This is a published concept put forth by Roman Landes, who said the following applies to most all knives

"He classifed steels into three groups, type I, type II, and type III mainly based on carbide volume, 0.5-5%, 5-15%, and greater than 15% respectively. These groups needed different angles to both take and hold a high polished sharpness, 8-12, 12-20, and 20-30 degrees per side respectively. The greater the size and volume of carbide, the greater the angle required to keep the edge stable."

Please note that the above only applies really if you are taking the apex to a high level or polish. If you prefer using more coarse finished edges then you can actually work much lower than this and the edge will sort of micro-fracture in use giving a type of low-level sharpness which can almost go indefinitely as at a certain point it just mainly stops wearing.

The interesting thing here is that higher carbide is said to increase edge retention, yet these steels require an increase in apex angles in order to not see drastic edge degradation in use. This increase in apex angle also simultaneously lowers the edge retention compared to lower angles. This is why I am personally not fond of the idea of just mega-sizing the carbide...

Very interesting post, thank you!
Steel novice who self-identifies as a steel expert. Proud M.N.O.S.D. member 0003. Spydie Steels: 4V, 15V, 20CV, AEB-L, AUS6, Cru-Wear, HAP40, K294, K390, M4, Magnacut, S110V, S30V, S35VN, S45VN, SPY27, SRS13, T15, VG10, XHP, ZWear, ZDP189
aprivetera
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Re: Sharpening angles for recent mules

#20

Post by aprivetera »

Thanks Traditional Sharpening! A plain 36" x 24" x 8" box showed up today that wasn't shipped far and didn't have much tape, so it was time to test the M398 mule. With 25% chromium and 5% vanadium carbides (according to the zknives website) and sharpened to 17dps, and I planned to see how long the edge would last cutting cardboard.

M398 has been trickier to sharpen compared to AEB-L and SRS-13/SUS405. First was breaking down the box into smallish 1sqft panels. Then 5 minutes on the medium BenchStone and another 5 minutes on the fine grit triangle ceramic file to get a coarse edge back to paper cutting sharp.

My non-scientific goal is to get ~2" squares to chuck onto the compost pile. After ~1400 cuts to get ~230ft of cutting distance covered, I'd say it maintained the initial coarse sharpness until the halfway mark. With a perfectly acceptable level of sharpness, nearly the entire box was done (just got tired of cutting!) and spent less than the original ten minutes resharpening.

Thanks Spyderco!

:bug-red-white
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