CPM MagnaCut | Edge Performance

[Deadboxhero]

Summary and analysis of testing.






I've been using MagnaCut for a year now as one of the early testers for custom knife making and for CATRA blades for Dr Larrin Thomas at Knife Steel Nerds before its release.

The spirit of this thread is to show testing with what's available for people to buy rather than a custom knife thats more difficult to get.

Also because I love Spyderco. I would not have gotten so obsessed about edge performance with different steels if it wasn't for Spyderco planting the bug with all the cool steels they release.

As a ravenous steel and edge junkie, it is my pleasure to share with you all here.



I'll start with Two MagnaCut Mule Team knives and branch out from there.



First, the edge retention between the factory edge and a more time consuming low angle hand made edge.

I also want to share testing between MagnaCut at 62.0 and 62.9rc and what the 0.9rc can make in the same steel if any.

This will be an ongoing thread so more things will be added to this original post overtime.

First off, I want to say special thanks to my friend Phil Wilson who taught me the ropes on cutting rope . Phil was nice enough to let me visit him at his shop several years ago. It was very insightful for quality control of custom knives and fine-tuning heat treatment. If some of you new guys are not familiar, Phil Wilson is basically the Godfather of using high alloy steels for knife making and the edge retention community owes him a huge debt of gratitude.



He is a living legend.

Thanks Phil.

I also want to thank Dr. Larrin for suggesting using a more of a logarithmic style for sampling the data points with the BESS tester.

Also thank you to Jim Ankerson, when I first got into knives I was enamored by his rope cut testing and his quest testing knives to find out what does what.

About the BBB Rope Cut Test.

My Rope Cut test has been modified over the years to try to reflect differences between things to the best of my ability.

One of the big problems with I found with rope cut testing is knowing when to stop to compare between things being tested for.

My test uses a fixed amount of cuts, which I was inspired by from CATRA.

127 Total Cuts.

One of the big problems with cut testing is not knowing the sharpness before and after in a quantifiable way.

I use the Edge On Up, BESS Sharpness Tester PT50A

The PT50A is used to measure the before and after sharpness but also to measure the change in sharpness throughout the rope cutting.

By doing this we can see the different rates of dulling between things.

There are definitely some nuances with the tester but I'll save that for another topic.

The BESS Sharpeness tester measures in grams how much weight is needed to cut the BESS media which is like a thin filament string. I tension my BESS media to 100g for better repeatability.


A BESS test is taken at

0,1,3,7,15,31,63,127cuts


If the Bess scores in grams are lower and follow a lower trend line than it is "sharper" than the others after 127cuts so we can assume it has more cutting edge retention.

This clever idea came from Dr Larrin who proposed that since the rate of dulling is faster in the beginning, it would be best to take more tests in the beginning rather than near the end.

My old test was 5 sets of 20 for 100 total cuts but they were interesting things happening in the beginning that I wasn't able to see with measurement.



The edge that was selected for this testing is the same as the Knife Steel Nerds CATRA test edge except at a 14dps rather than a 15dps, this makes it easier to cut rope which can be rather difficult. In the future we could also compare different angles.

The 400 grit is selected based off of years of experience as the best compromise between being able to slice the Rope aggressively, yet not so coarse as to not be reasonable for what people would carry and use.

Moving up higher in grit would make the edge "sharper" with a lower starting BESS score but the smoother Apex takes considerably more Force to draw through thick Manila rope and make a cut in a single slice. A polished edge however will take less force than a coarser edge only if both are used in pushing straight down into the Manila rope however push cutting by nature is more of a cleaving action than a cutting action as I learned from Phil Wilson.


The Rope is 3/4" five star Manila rope, I learned from Phil that you need to order a full coil from a quality manufacturer online. The moisture content before testing was at 12% at 68-70°F sitting inside my house in a dry place. Moisture content will change with different climates and humidity since the Rope will absorb ambient moisture in the air or lose it in drier climates

Drier rope is more difficult to cut.

I am cutting the full braid, the Manila rope is a natural product so it's not going to have the highest consistency but we can still see trends moisture is the biggest variable, lower moisture makes the rope more abrasive and more difficult to cut, this data is built with the same moisture content at 12% which is just from resting inside the house on the bottom shelf of my sharpening cart.


The Rope is being cut in one single pass which takes around 50-70lbs of force per cut , the area of the edge thats worn the most is the belly of the knife so that's where the BESS tests are focused.

It takes less force to saw the edge back and forth but it's easier to quantify a single cut and since we can use the BESS tester to quantify the rate of dulling, we don't need to the sawing motion for our objective.

With it requiring 50lbs to +70 lb to make a single cut in Manila rope the cutting surface is very important I'm using a very soft synthetic poly board that my fingernail can dig into easily, the past I used a bamboo cutting board which wrecked havoc on the edges. If I used thinner rope such as 1/4" it would not take as much force to cut in a single pass. I like the thicker rope because it has more of a dramatic effect on dulling with less cuts, also if your Edge is not good it will not be able to cut only extremely sharp edges are able to make it all the way to 127 cuts.

Thicker rope is more difficult to cut.


The goal of the testing is to see which knife retains the lowest BESS sharpness value in grams in 127 single slice draw cuts in 3/4" manila rope at 12% moisture.

This test should not be used to comparison to results from other tests/testers. This test is built to be its own standalone data set.

No test is perfect but the goal is having control tight enough to see differences between things enough to look at a trend between them.

I am not here to tell you how many cuts your knife is going to do, that is ridiculous and often the reason why controlled testing is downcasted "my knife cut longer/less" there are many variables for why that is.

I'm just trying to show in a more controlled environment what are the differences between the things we are testing for, so if your experience is different you know how the things stack and can rule out other things as to why or why not something is not performing to your expectations.



I purchased Two Mules from Spyderco from the website, it was quite a frenzy.

Both were hardness tested with my calibrated hardness tester multiple times for an average hardness reading.

First mule was 62.0rc.

The second mule was 62.9rc.


The batch range from Spyderco is 62rc to 63rc.

Sal said his Mule was at 62.6rc in another thread and Larrin made an Instagram post about his being 62.7rc.

Why the variation?
When heat treating in large batches there will always be inherent variation just like there's always inherent variation in everything. It is simply not cost-effective to heat treat one by one unless somebody is willing to pay more.

So, I thought it would be really interesting to see the difference 0.9rc can make an edge retention testing on rope.

I also thought it would be interesting to test the factory edge. My reasoning behind this is I see a lot of people are making evaluations on the MagnaCut steel based on the factory edge as it came, my personal opinion is one should not evaluate steel without first putting their edge on it.



Here are the results between the Factory Edge and my 14° DPS Edge at 400 Grit.




This was with the 62.0 rc MagnaCut Mule, I first tested the factory edge than I sharpened it and tested my edge.




The factory edge was NOT able to complete the 127 cuts in my test and died at 48 cuts.

The dots represent the actual data collected with BESS testing, the curved lines are showing the trend. We can see that the red line is lower than the blue line meaning the 14dps edge I made has more Edge retention.

While not a big surprise the lower angle won, I wanted to share the difference between these edges and why I never test the factory edge, ever.

I wanted to share this to show that for serious users the factory edge is a placeholder more than it is something to use to evaluate the STEEL which is not meant to say the factory edge is unusable.

CALM DOWN

The factory edge will still be able to cut things.
I'm just showing the difference between things more objectively.

I am thankful we are able to get a fantastic product for a very reasonable cost thanks to the volume Spyderco is able to achieve with their production.

I think sharpening is a very crucial skill for people to really get the most out of all these different steels, at the end of the day It's the end user's responsibility to sharpen and care for their knife.


Again, The factory edge didn't complete the 127 cuts in my test and died at 48 cuts.

Why?

I could no longer consistently make a cut in a single pass without needing a more saw like motion to get through the 3/4" in Manila. The force was well over 100lbs to try to make a cut and required me to try to use my body weight to assist in the slicing to which I only had the endurance for 48 cuts before the edge became so dull that I could not make it cut in a single pass.

The initial sharpness of the factory edge was duller than the average factory edges on folders and also thicker. It was able to cut paper but not shave consistently.



Bare with me, I'm going to take about the factory edge angle in great detail because geometry is everything.

I measured the edge geometry using a CATRA laser Edge goniometer to reflect a laser light off the bevels that then shows how many degrees the bevel is at. This is a very important tool because geometry is the biggest factor when testing things.


Often times you'll hear people talk about differences between steels when really it's just a difference in the edge geometry. Thicker edges will be more durable, thinner edges will cut more. It's an inverse relationship.

I will say boldly that if you are not using this device to measure the angle you have no idea what you're angle is which will make comparing things very difficult.

We can see based off in the light reflection pattern that the edge is a hollow edge created by a wheel.


The test area on the factory edge was an included angle of 35°. The factory bevel is asymmetrical, if was symmetrical it would be 17.5° per side. The right side of the blade had a steeper angle.

The edge bevel also was not the same angle throughout the length of the edge the angle twists down the bevel.






The factory edge was at a lower angle towards the heel and at a thicker angle towards the tip.

For simplicity sake I'm going to use degrees per side (dps) even though it's asymmetrical despite the looking even on both sides. It was near 20°dps at the tip and 16.5°dps at the heel. The area that saw the most use in rope cutting (which is the test area) was 17.5° dps. The reason the bevels look the same width is because the grind is asymmetrical and the bevels are matched compensate for this.

Below, I share pictures of the tip area which is at a thicker angle than the test area and heel of the blade. You can see how it rotates in towards the tip rather than keeping the same angle. Even keener eyes will notice that the bevel is hollow which is confirmed on the laser goniometer and a good topic for another discussion.




Below are images of the laser goniometer measuring one inch from the tip area which is at a thicker than the area we are going to be testing.

The outer reflections are the edge bevel, the inner light reflections are the grind you can see we can match one or the other but not both because there is asymmetry.

Different light reflection patterns can tell us more about the coarseness of the scratch patten, it's orientation and whether the edge is hollow, convexed or flat which for brevity's sake won't be discussed here.





Because the bevels look the same but change when we use a fixed angle sharpening system it means the grind is asymmetrical not the bevel.


If we used a sharpening jig with a controlled angle the right side of the blade will have a wider bevel due to the grind.

This is one of the advantages of free hand sharpening is it easier to get symmetry on the bevels despite the grind. There will always be slight convexity towards the apex to freehand sharpening as well, which is a topic for another time




The lower edge angle had a significant advantage over the thicker factory edge despite the small increase in the behind the edge thickness. The cutting ability and the rope also improved, it didn't take nearly as much force to cut a single slice and the 3/4 in Manila rope.

The edge angle is also completely 14° DPS with no other angles hiding on a flat bevel, this is important because if we want to compare differences between 14° 15° 16 °or 10° per side we need to have them distinctly different so that we can know what we are comparing since edge angle is the biggest factor for edge retention and durability if properly apexed and deburred.

Next we compare the difference between 62.0rc and 62.9rc in edge retention.




I suppose this should be no surprise, if the steel is harder than the same steel than it will stay sharp longer with cutting because the apex will resist being worn down meaning it will stay smaller with the same amount of cutting.

While there are caveats to higher hardness having more edge retention that is for another discussion.



I'll add more to the thread as time goes on.
I'm sure there's plenty of typos to fix as well so forgive me.

[Deadboxhero]

*Update 2/21/22

New video about optimal hardness of CPM MagnaCut by Dr Larrin Thomas, some of thes testinf here was used in that video, Thanks Doc








This is how sharp all the knives are before testing.



This is how dull the 62.0rc MagnaCut Mule was after testing.

So you can get an idea how much sharper the 62.9 rc mule was after testing, meaning the higher hardness retains sharpness better and has more edge retention on cutting rope.



Something edge geeks are always curious to know is which knife strops back better after going dull. I suppose it's no surprise that the harder MagnaCut will strop back better but I thought it would be fun to show this empirically along with the BESS value.

We noticed that the softer MagnaCut (62.0rc) hesitates more in newsprint, they both will cut printer paper but a keen eye will observe that the 62.9 is cutting it better. Neither of them stropped back to the full sharpness they were before testing and nothing ever does.

Neither one stopped back to treetopping sharp or hair popping sharp but I only stropped them three passes per side on 1um. The harder MagnaCut shaved slightly better than the softer MagnaCut.

About stropping,
Stropping is an enhancer, not a creator it's really best used to finish an edge fresh off the stone but it can help a worn edge get a little sharper and cut longer so that a fancy blade is not being excessively sharpened.

We cannot strop or hone indefinitely, it's used merely to prolong the use of a worn edge before finally needing to break down and sharpen. The harder MagnaCut blade will last longer because we won't need to sharpen it as much and can get away more with stropping and honing to prolong a worn edge since sharpening will remove metal and over time the blade will shrink.

There is still fatigued metal at the edge, to get the truly sharp edge back I would have to reestablish the apex again on the stone and then stop if I wanted to achieve full sharpness. When I look at a knife I always look at the blade as a reservoir of steel for new edges.



Here is an up close look at the edge prior to rope cut testing, making sure that there is no wire edge, residual burr or fatigued steel.

I also thought it would be neat to share what rope cutting looks like with magnification.



Sal was kind enough to let me use his MagnaCut
PM2 knife. Being one of the first pieces of MagnaCut to run through Spyderco. It's not going to represent the final production heat treatment and improvements that can be made but I thought I would run some testing and share.



I've had this Magnacut knife since fall 2021, However I didn't feel like I could share without doing a comparison with the other popular steels.

It took me a while to purchase these other knives and wasn't cheap so hopefully the effort here is appreciated.

Each was tested multiple times.






Getting the same edge angle is extremely important for making ANY comparison. Using a system is not a guarantee things are the same so its important yo use a laser goniometer if we want to rule things out.










Here are the test results for the pm2s that I tested with this rope cutting method.



The objective of this testing was to observe the loss of "front end sharpness" or "initial sharpness" and the transition into the working edge between these steels on the same model as you can buy them off the shelf all with a 14°degree per side, 400 grit cBN edge finish that has been carefully deburred without stropping and confirmed with microscope prior to testing.

All of these were hardness tested using my calibrated hardness tester using the ASTM e18-20 standard for best practices.

A disclaimer about the testing.

This test is a stand alone set of data and should not be compared to other tests. I did multiple test runs and ran an average of BESS scores, edge dulling is not consistent in real world and there is less consistency as the edge wears meaning more BESS tests are needed to average from as the edge gets duller.

These results will be different from the mule team because I spent more time retesting and running more averages on the BESS testing especially at the end of the test.

With the MagnaCut mules I only needed enough resolution to see a clear difference between hardness between those two in that data set.

We can retest those in the future if I have more interest and time to do so.



Also the mule knife is not pm2, the profile of the mule team edge doesn't have as much curvature as the PM2, so the dulling may be different which is something that can be explored further and ruled out in the future.

There were some effects of edge fatigue which made it so I had to retest especially on some of the knives more than others but that's for another discussion.




This test should be looked at as how these specific knives/batches line up.

There will be variation between batches in the same steel and even within the batch when it comes to hardness.

I think folks need to really respect the volume these are made at, which will always be a trade-off for precision, and exactness but at the same time custom work is not as scalable as production work and you have to appreciate the value you can get these knives at which are also more available than custom knives.

So none of these should be thought of as fixed points to say these steels will always line up like this.

Some of these knives will be harder or softer within the tolerance.

So we should look at these values as to how these specific knives line up with each other.


Here are the hardness results.







The MagnaCut Pm2 I have here is not a full production model yet, this was part of a small experimental batch and will not reflect the actual production MagnaCut that will be available in the future. So, hopefully those reading here have attention to detail and can put this into context if not I won't share such detailed testing in the future if it's too much for the lay person to handle.

We have already seen that the Mule team has a higher hardness range and there is potential to see even higher hardness for increased edge retention in the future which should take more advantage of synergizing MagnaCut's attributes.

The CPM Cruwear Pm2 Micarta is significantly harder, even harder than what has been run on past CPM Cruwear knives. I would look for this model specifically to get this hardness range rather than some that were made in the past.


The M390 from DLT red g10 was also surprisingly hard, I've seen past batches of M390 Pm2 knives run at 61-62rc more. I am not sure if this is an outlier in the batch. I didn't heat treat it and I don't have the time and temperatures used so I can't comment further.

The Elmax and the s45vn Run slightly harder than the s30v we've seen in the past which is pretty exciting. Yet, it would also be interesting to see s30v run harder as there have been slight modifications to its chemistry since its first inception that haven't been advertised such as the nitrogen addition.

It's nice to see the 52100 with a respectable hardness, I saw another 52100 Pm2 knife test at 62.8rc well the carbide volume is low and the iron carbides are soft higher hardness is better for taking advantage of the increased edge stability 52100 can offer.



In Dr Larrin Thomas's excellent book "Knife Engineering" on pg 81 there is a great graph of the CATRA testing showing cards cut over cutting cycles, the three steels here are drastically different from each other you'll often see claims of steels like AEB-L holding higher front end sharpness.

The graph here shows that they seem to dull at the same rate until we get into the working Edge which then shows more separation as the carbide volume and type in the matrix start to take over more.

It was my hope to explore this area more.



My testing will focus on this red circle area which will have less separation than if we tested further into the working edge. At 127 cuts in 3/4"manila rope we start to transition into the working edge.




A working edge is an edge that will no longer shave or cut paper as cleanly or consistently. We notice this transition around 300g-400g BESS
The hair shaving edge starts to drop off at 200g with the edge no longer able to scrap shave thin arm hair at 300g BESS. Yet when closer to 250g the ability to scrape shave remains.

This is specific to a 14°dps 400grit edge. so the values are not universal, if we change angles and finish than when we stop shaving hair etc will change. That is something to explore at a later time.


Here we can see the increase of grams needed to cut the BESS testing media over the number of cuts to a total of 127 single slice cuts in 3/4" manilla rope at 12% moisture. BESS testing was done at logarithmic intervals to watch the increase in weight needed to cut the media grow with more cutting volume.

The increase in weight need to cut the BESS media can be thought of as loss of sharpness.







Intial Sharpness decreased rapidly in the first 25 cuts with more separation in sharpness from here.

The strongest factors for retaining initial sharpness or front end sharpness is hardness and carbides. If everything is sharpened the same.

These results should also be thought of as specific to these knives not all the M390, MagnaCut etc and also specific to a 14°dps with a 400 grit metallic bonded cBN finish.

If somebody is experiencing a difference from this result I'm concluding it is because of how they are sharpening not the steel name.
There are significant factors that people need to rule out for their experience, use of anecdotal accounts and testing are.


1. Edge angle- which is almost impossible to do
without using a laser goniometer a difference in 1° dps makes a huge difference in edge retention/durability if you want to compare things.

2. Abrasive type- I strongly feel its important to cut all phases inside the steel matrix.

3. Deburring and fatigue- the most difficult part is making sure that the edges are properly deburred and not fatigued.


It was interesting to see that there wasn't much separation between MagnaCut, S45VN and Elmax in Intial Sharpness if the hardness was similar.

If we increased the total cuts in rope past 127 we will see more separation however the focus of this testing is on loss of initial sharpness not pure endurance.

The S45VN being slightly harder on this exact knife compared to Elmax and MagnaCut im sure played a role in it being slightly better, MagnaCut has the lowest carbide volume next to 52100 which improves its toughness but not its resistance to wear on cutting rope.

Hardness is important for resistance to deformation so while MagnaCut does have an advantage with its finer carbides for increased edge stability at 61.4rc on this experimental knife it wasn't hard enough for it to shine.

MagnaCut should be run harder than 61.4rc to see higher performance in edge retention and resistance to edge deformation if used on a small pocket knife made to cut like the Pm2 at 14dps with a 400grit finish to cut rope which will translate to higher edge retention with anecdotal accounts in real world use.

It's very interesting looking at the 52100 the Cruwear and the m390.

While the 52100 and Cruwear were significantly harder the m390 still maintained its Intial Sharpness better thanks to its higher carbide volume.

52100 has the softest carbides at the smallest volume which is good for edge stability but not for edge retention. While some have claimed the front end sharpness was higher for them that seems to be due to sharpening technique, skill and stones used rather than the steel itself, 52100 is more responsive to mediocre sharpening.

It should be noted that the 52100 took more force to separate rope near the end of its 127 cuts will have to quantify this using a load cell at a future time.

Conversely the M390 took the least amount of force to cut rope near the end of its 127 cuts.

I was very surprised to see how well the Cruwear did but it was the hardest out of all these knives and that something more specific to this batch rather than all Cruwear on previous models and batches.

Hardness is an important component for front end sharpness/Intial sharpness. Along with carbides, their type and volume.

What increased hardness does is if done properly is it translates into resistance to deformation with high performance cutting geometry.

Resilience often doesn't get as much love as toughness it seems.

So seeking knives that have the highest toughest levels like S7 and CPM 1V, 3V will not be great for edge retention unless the primary mode of edge loss is due to sudden shock/impact, which is something that can be explored at a later time.

We can explore the edge durability between these knives at another time.

When production Spyderco MagnaCut comes in a Pm2 we will see it harder which will be interesting to test when the time comes.

Please forgive me for any typos here.

[Evil D]

Will be following. This is all a lot of stuff I've been wanting to do if I only had the time to do it. I also noticed the blade grind and bevel inconsistencies, I even managed to get my apex off center trying to compensate for it before I realized what was going on.

[Deadboxhero]

Will be following. This is all a lot of stuff I've been wanting to do if I only had the time to do it. I also noticed the blade grind and bevel inconsistencies, I even managed to get my apex off center trying to compensate for it before I realized what was going on.

Thanks David, yea I've always considered any edge I get to be a placeholder.

I figured it was important to point out not for any kind of witch hunt just an FYI since people are going to be evaluating how MagnaCut sharpens and may not factoring in the difference in effort it would take to put a given geometry they want on it.

Also, since folks will be evaluating the edge retention and the durability and the geometry is also a big factor for that.


I'm sure you would agree David that it seems like a lot of people in the knife community think of sharpening as an afterthought, just for maintenance when really they need to look at it as the key to True Performance.

[Matus]

Thanks a lot for the detailed report Shawn.

[Deadboxhero]

Thanks a lot for the detailed report Shawn.

Thanks brotha, More to come.

[Evil D]

Will be following. This is all a lot of stuff I've been wanting to do if I only had the time to do it. I also noticed the blade grind and bevel inconsistencies, I even managed to get my apex off center trying to compensate for it before I realized what was going on.

Thanks David, yea I've always considered any edge I get to be a placeholder.

I figured it was important to point out not for any kind of witch hunt just an FYI since people are going to be evaluating how MagnaCut sharpens and may not factoring in the difference in effort it would take to put a given geometry they want on it.

Also, since folks will be evaluating the edge retention and the durability and the geometry is also a big factor for that.


I'm sure you would agree David that it seems like a lot of people in the knife community think of sharpening as an afterthought, just for maintenance when really they need to look at it as the key to True Performance.

Many people do look solely at the steel as the source and culprit of all performance pros and cons. It's one reason I don't follow anyone else's test results very closely or compare them to my own, but I try to do my own stuff as closely as I can so at least I know my own bevels and such are as comparable as I can make them. Even just sharpening abilities alone will give two people different results, I think a lot of people assume they do well enough and immediately blame the steel or even worse the heat treat.

[Deadboxhero]

Will be following. This is all a lot of stuff I've been wanting to do if I only had the time to do it. I also noticed the blade grind and bevel inconsistencies, I even managed to get my apex off center trying to compensate for it before I realized what was going on.

Thanks David, yea I've always considered any edge I get to be a placeholder.

I figured it was important to point out not for any kind of witch hunt just an FYI since people are going to be evaluating how MagnaCut sharpens and may not factoring in the difference in effort it would take to put a given geometry they want on it.

Also, since folks will be evaluating the edge retention and the durability and the geometry is also a big factor for that.


I'm sure you would agree David that it seems like a lot of people in the knife community think of sharpening as an afterthought, just for maintenance when really they need to look at it as the key to True Performance.

Many people do look solely at the steel as the source and culprit of all performance pros and cons. It's one reason I don't follow anyone else's test results very closely or compare them to my own, but I try to do my own stuff as closely as I can so at least I know my own bevels and such are as comparable as I can make them. Even just sharpening abilities alone will give two people different results, I think a lot of people assume they do well enough and immediately blame the steel or even worse the heat treat.

Yeah good point, I remember there was a thread on bladeforums where somebody was swearing that his Buck 420 HC was out cutting his Spyderco vg-10 in cut testing and use.

Even though technically the vg-10 will cut longer if all things are equal.

So for him, 420 HC was working better for whatever he was doing or not doing to both knives.

The end user is the biggest variable.

[skeeg11]

Mucho thanks!!! This is the kinda stuff that really gets my attention. Looking forward to future installments.

[JSumm]

Thanks Shawn for all of this effort. Subscribed to topic to follow along. And thanks to Phil. I'm sure we owe him more than we know.

[Airlsee]

Great info, with not entirely surprising results, thanks for putting in the work Shawn! I didn't expect the factory bevel to be quite as disastrous as the testing revealed. In the end, geometry cuts and HRC keeps it cutting. Now I need Gritomatic to restock their goniometers...

[Ramonade]

Thanks a lot for sharing all this work!

I was feeling a bit guilty for reprofiling or simply sharpening any new knife I get. I feel it less now ^^. I kept some at factory, but when I see unevenness in the bevels I try to know why (doesn't end well depending on the cause, like Evil D said).

This instrument, the laser goniometer seems a direct answer to wether the uneven bevels come from the secondary or primary. I'll know when I'll receive and sharpen the MT35P.

Looking forward for the next posts in this thread.

[The Meat man]

Great stuff. Thank you Shawn!

[Bloke]

Thanks heaps, Shawn!

[NCJohn62]

You da man Shawn! A lot of what I do now with knives and my purchases are result of what I've learned from you and other edge retention fanatics.

[vivi]

Initial findings do not surprise me. I've always experienced superior edge retention in any steel once I grind away the factory edge, even if I try to sharpen it at the same angle. Dropping the edge angle makes the comparison even more dramatic.

Thanks for your hard work. I'll be watching this thread along with the corrosion resistance one.

[attila]

Thanks, Shawn for your expert data gathering!

I was curious, which date codes your mules have on their boxes? Additionally, if different, do you remember which mule went with which date code?

Thanks again!

[Eli Chaps]

Outstanding as always Mr. Houston.

That Phil Wilson video was, and still is, my favorite of yours. It always stuck with me when Phil said about steels (paraphrasing) they all fail, you can have chips or rolls.

I wish more people would approach sharpening much earlier in their knife ventures. Be it a good fixed system or freehand. It drives me crazy how many people spend serious coin on knives with no ability to sharpen them. Not only are you missing out on better edges, you're missing out on the personalization of the experience. The failures and triumphs are all part of it and make this such a deeper and richer hobby.

Sub-optimal factory edges are pretty much common place. That isn't a slight on Spyderco, it's just the nature of the volume-manufacturing beast. This is such a serious thing that many Japanese smiths won't put that last finishing touch on the bevel. Believing that is best left to the user so that it is both what he/she wants, but also for the bonding with the blade.

Looking forward to more and as always Shawn, thank you.

[Doc Dan]

This is good stuff. Thanks. I am waiting for more.

[Wandering_About]

And that's why I spent the effort on reprofiling a couple Maxamet knives. Geometry cuts!

Thanks for the info Shawn.