60 Grit Testing

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IGP1785.jpg



Well !
Recently I has a CrazyFox knife go from a 50 slice fail ...
To a 550 slice fail .. Yeah ! , that's only a 500 slice difference or like 1000% ...
That's crazy !

I know in the past I have used a 80 grit diamond to lay down an edge on ( Softer / cheaper / steel ) and I gained edge holding .
So is this a case off samo / samo ?
Or was it the angle of the bevel that was responsible for what was essentially a horrific increase in performance . ( ? )
In anyway , this enquiring mind wants to know ! And you the reader are free to come along for a ride ! ( If you so chose )

We have some 10 previously disappointing knives , one of which is another CrazyFox D2 . And if mem serves that CFD2 did a 200 fail on a 220 grit wet stone grind . Be interesting to see what happens this time around .

The Grind

I have a 200mm X 25mm grinder wheel , being some 60 grit .
With the help of my 3D printer , I printed out some spacers so the grinder wheel would go on the wet stone grinder .
And that crazy CrazyFox knife was the first knife to be ground ( due to the monolithic build of the knife ) , as there was a lot of material to remove to make a new edge profile . And the result was a 1000% increase in edge holding . ( color me shocked and awe struck ) It's not every day you see a 1000% performance increase .
So I must start a process of elimination ..
Was it the GRIT , or was it the ANGLE of the bevel ?
And as this post might suggest , I am starting with the grit and 10 other disappointing knives .
Im too pooped to pop after hours of grinding ..
So as the clock ticks and tocks , I will try and get thru these 10 knives as soon as possible !
 
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Knife Number One = Civivi Dogma .......

I always thought this knife a DOG ! No matter the amount of effort , I could never come close to D2 performance levels .
The best number I ever achieved was something like a 200 slice fail on the rope .
And the worst was sub 100 .
I did buy some HRC files , and the 60 HRC file skates ... ( So the steel is hard - at least )
On the grinder we go - again !
This time with the 60 grit grinder wheel .
Have you already thought of a number , cos I was surprised when the knife finally gave up the slice at some six hundred slices of rope !
That's right , a poultry four hundred slice increase over the previous best .
Ok , so this is only knife number one in the test so far .
And a important question begs answering . If this 60 grit stone does this to disappointing knives ?
What will it do for good knives ? ( A question for another time )
Video soon :

 
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Knife Number Two = CH3509

Apparently this knife took part in my bevel angle test & at 18 degrees did a 250 slice fail .
250 is far short of what I would expect from a D2 Knife .
So , this knife has been included in my 60 grit test series ..
Range of disappointing knives , re ground with a 60 grit grinder wheel on my wet stone grinder .

Well the results seem to speak for themselves as I threw in the towel at some five hundred and fifty slices .
This is only a three hundred slice increase on the previous best . ( " only " )
It would be fair to say I would never ( previously ) had expected this knife to make five fifty !
Even now typing this , it's hard to believe .

These results seem to almost fly in the face of common thinking !

Common Thinking

The finer you make the edge , the better the performance !
In other words a mirror polished edge should cut better and longer than a more poorly finished edge !
These results , are kind of the opposite of that .
Admittedly with what I would have originally labeled junk or poorly made knives ( blade steel ) .
Maybe you can make a silk purse out of a .........................

Anyways , we are two knives down a journey of discovery .
Only 8 more knives to go !

 
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Here's where the sharpening mavens hang out on BF : https://www.bladeforums.com/forums/maintenance-tinkering-embellishment.794/

Maybe you could post a compilation of these 60 grit results there ^ , when completed ?

They may have some ideas / explanation .

My only notion is that the 60 grit makes a toothy edge that acts almost like serrations .

Serrated edges will still cut when PE are done for .
Yes , it makes for a some what micro serrated edge ..
You wont notice on fleshy stuff , shaves hair like it's nothing , but you can feel the serrations on printer paper .
The harder the steel , the less you feel it , cos harder steel cuts smoother . ( Smaller serrations )
So far the two knives tested skated my 60 HRC file .. So hard steel !
What I might test in the future , is edge retention loss when the edge is stropped back .. ( I would imagine those serrations will diminish with use - might have to test that )
Speaking for myself , I want edge retention . And I want to be able to easily strop the edge back . ( Stuff to do in the future ) Also , what will a better knife do ? ( oooh , a 1000 slice knife ? )
 
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Knives 3 & 4

Knife 3 = Leupold 440c


From memory a very disappointing knife .
I've had it for while and I dont remember it doing more than 100 slices of rope previously .
Steel does appear to be rather soft , unfortunately the blade is coated ..
So no HRC file test ..

But , with the 60 grit edge I pulled a 350 slice fail out of the hat .
All things considered , is a rather good result for 440c in general .
Just dont have any data on previous testing ( My bad ) . But I did consider it a junk knife .

Knife 4 = Gearbest D2

I will call this a mystery steel knife .
No way in heck is it D2 , in fact this pattern is known for Faux Steel .
So a 300 slice fail with the 60 grit edge is no surprise . Cos it was a huge disappointment from initial testing ( Again that lack of early data ) .
But , a 300 slice fail makes this knife useful . ( With the 60 grit edge )
Also the edge was very toothy , once more suggesting soft steel . Probably the toothiest blade tested so far .
I simply don't remember the previous numbers for this knife , but they were not good .
I guess for a $20 banana knife , 300 slices is ok ( 60 grit edge ) .

So it looks like improvement all around . 4 knives down .
And the 6 remaining knives are quite possibly equally disappointing !
I mean that Y-start failed at 50 once .. And after a lot of edge massaging , did it ever pass 100 ?
I should keep a log book ! ( Should )

 
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Knife test 5 is null and void ...
The edge rolled , thus invalidating the test .
Oh dear ! This is a cheap nasty piece of steel .
But it did strop back strong , so that's something ( I guess )
 
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Knife Number 6 = Spider ? co ( Is it a real one ? ) HRC file test , 55/50 The 55 just bit the steel !

Yeah , time to continue 60 grit testing .
This knife exceeded my expectations .
On the rope we got to some six hundred and fifty slices . This is simply excellent performance from a knife that has disappointed for almost a decade .
It was a terribly windy day , but despite the wind I was able to get a result .
Now , six fifty is the realm of premium steels .. So for this knife to get into that region is surprising .
So another turn around for a disappointing knife .

Re sharpening ..

Two passes on the hard leather ( 1 pass each way = 2 ) , no slicing paper .
Four passes on the hard leather , it did slice paper but after a few inches hung up on a crease .
Six passes on the hard leather and it sliced the paper cleanly
Ten passes on the hard leather and it was getting smoother .
Sixteen passes and better again
At 20 passes on the hard leather , the knife was very smooth thru the paper .
 
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Knife Number 7 = Y-start D2 (?) ( ? on the D2 )

So started off ok and then around 200 slices there was a small niggle .
At 250 slices there was an issue
And at 300 slices there was a fail .
At and the root of the problem a rolling edge .
Previously this was a really poor performing knife , Bad !
So at 300 ...... Well it stropped back easily ...
So not a very good knife .. But ......... That 60 grit stone is doing a bang up job ..
I know this knife previously failed at 50 , so 300 compared to that is ..............

 
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Sorry if I missed it but what edge angle are you putting on these?
Aiming at 20 degrees ...
I have had 22 degrees roll on me .. Just comes down to the steel ... Just cos steel is reasonably hard , does not mean its tough .
Depending on the steel , how it's cooked , soft steel can perform well . It's a crazy , crazy , knife world !
And the only way to know , is to test .
All these knives are what I would call FAILS .
Previously all these knives had a guided 22 degree edge .
That 22 deg edge was my standard edge ( Especially for testing ) , and decent D2 would do 450 with that edge .
+ A lot of factory knives are right around the 22 degree angle for the edge .

I am yet to test the difference the angle makes .
As for now , I just grabbed a hand full of knives out of my JUNK knife box and ground them ( wet stone grinder ) with a 60 grit wheel .
After this test , I will test what angles do ... ( Gains / losses / rolls ) I will need to use a knife that performs well with a finer edge . ( Finer Finish )
And some time ago I tried to test from a low grit to a polished edge , but it was too much work to put a mirror edge on a knife .
Since then I have collected more DIAMOND up to 3000 grit , so might try for that mirror polish in the future .
 
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Knife No8 = Navy 440c
Yes , a past disappointing knife that ended up in the junk knife box .
I dont remember this knife making it past 100 slices previously .. But I can't be 100% , it might have gone slightly higher ?
Anyways , I am 100% sure it never made it anywhere near 350 slices ..
Video Soon ... It's a cool ( 13c ) wet day today .. So the paper slicing was done inside . ( Un avoidable )

 
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What happens after ?

That's a good question ! What does happen after the 60 grit testing .
I will simply test the other Variable , the edge angle ..
I might have to start @ 22 degrees and work my way down in 2 degree increment's until the edge rolls ..
And for that , we will need a known decent knife or maybe a known decent knife and a fail knife ( failed to impress )
In fact , I have a few TwoSun D2 waiting re testing that disappointed .
Should all prove to be interesting .. ( Let me have a look see )
YES ,,,,,
my TwoSun TS09 ( ground 250 ) & TS208 ( guided 250 ) , both being D2 and both disappointed ..
Hmmm , these two and maybe a 3rd knife that hit what I would expect from D2 @ 22 degrees
 
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Knife No9 = WithArmour 440c ( WithArmour Finches 440c - Factory 40 / 90 with a new bevel guided )
So we have some documented results for this knife ...
Factory 40 slices / guided 22 degree edge 90 slices ....
Oh dear! That's some poor performance !
Now how about that 60 grit edge , how did that go ?
Four hundred and fifty slice fail .. Oh you read that right !


Next knife and last knife is the Crazy Fox D2 previously tested @ 200 slices for a 220 grit wet stone grinder edge !
Again not very good , there be a review posted in which I was some what scathing ....
So one more knife to go !
 

willc

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I really like your dedication to knife testing and I am pretty sure the improvements have been due to getting better geometry and the extremely toothy edge.

You should post on the Maintenance and Tinkering section a video of you sharpening a knife.
I think it is neat that you have a water cooled system with a regular 6” grinder.
I sharpen a lot but I don’t use powered tools often unless the knife needs major work.

Good luck with your testing.
 
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Hmmm , yes !
I will have to do a video of me sharpening a knife @ 60 grit , and then testing it !
Would have to be a known performance knife ( tested + documented ) & I should try and match the angle of the grind .
I should have something ...
 
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We have a volunteer ... The Kershaw Highball .... I will have to dig it out ..
 
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Kershaw gets a 60 grit edge , at the same angle as the previously tested 220 grit grind .
We still have the CrazyFox knife to test ..
And then we can get to some angle testing .
 
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Knife No 10 = CrazyFox D2 ( Previous result )

Ok , last knife in this series of tests .
Previously did 200 slices with the wet stone grinder edge ( 220 grit grinding wheel )
This time ....... 16 Deg C / 65% Humidity
Returned a Five Hundred Slice Fail . Only a Three Hundred Slice Increase on the previous result ! ( Only )
Though with this one , there was a change in the angle of the bevel .
Which is why , there will be a control test with the Kershaw .
This was entirely about making junk knives - not junk knives ! And some results were Ho hum and others quite outstanding .
Video Soon .

 
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