All About Pocket Knives

180 Grit 22 degree guided edge - 150 slices of rope .
This is my go to edge and it simply fails to perform . Sharpening the TS123 , the steel did feel really soft . The 180 grit diamond ate the steel like a hungry man eats a sandwich . I have to be honest and say I really did feel disappointed at this point , I had no plans to put an edge on this knife with the whetstone grinder , but at this point I felt I had nothing to lose .


Whetstone Grinder / Knife Sharpener Edge
I just don't know what to say ?
A) This edge is rough and not paper friendly at all , on other things though ! Flesh / cardboard / rope and such , it is very slicy dicey . I have accidently , lightly brushed a finger against this edge and there was no escape . The result was a sliced finger .
B) It is some what subjective - Paper cut test - when a fresh edge cuts paper so poorly ! How do you call it ?
C) That's why I put it on video , that way the viewer can call it where ever they like .
D) I got to 600 slices . Yeah , that's crazy . Especially when the steel is so soft . I am going to test that grind profile on another knife ( CH3509 )
E) I actually did change the grind profile from what I normally do , so that will need re testing with another knife .

TwoSun TS123 -
It did perform very ordinary on the factory edge and my go to 180 grit diamond cut 22deg edge . I have another TwoSun ready to rock N roll with the old ground edge and what I might do is after testing it , switch over to this new grind profile and see what's ?
The TS123 . Simply feels great / Looks great / great walk and talk / nothing to complain about except the edge profile having a dip in it . Was it some one falling asleep at the grinder or is it supposed to be that way ? ( Don't like it )
If I had to score the TS123 on everything but the blade , I would call it at 9/10 . The blade is a bit of a question mark . It did not respond to a traditional edge at all and only seemed to work with an experimental grind profile off the whetstone grinder . Oh dear oh dear !

Guided Knife Sharpener / 180 grit 22 degree ( 800 grit de bur )
At 150 slices , this is simply a failing mark for M390 . What was the cause for this failure ? The knife was sharp , there was no bur and the edge did not roll . And the steel did feel rather soft when sharpening . Certainly I would call the knife bad if I had stopped here . On decent D2 this edge has done 450 .

More Edge Testing
So it looks like this knife just really liked the Whetstone Grinder / Knife Sharpener . I put the same / similar edge on my disappointing CH3509 and it was still seriously disappointing . ( 100 FAIL ) Interesting ! I guess it pays to try more than one way of putting down an edge .

old4570, excellent work on your part to make such an informative post. Thank you.
The 'dip' in the blade profile is what is called a "recurve" and is seen on many knives. I do not understand the purpose of a recurve profile and it does make sharpening more difficult.
I am surprised to learn that the M390 steel blade is so soft when you sharpen it. And why it cannot cut paper but does cut flesh and rope i also do not understand. It could be that paper requires a more polished smooth edge whereas other materials are more easily cut with a more 'toothy' edge ?
Would be helpful to hear from others who specialize in blade sharpening as they might be able to explain your findings.
kj

I EDC, use, have sharpened and love my Hinderer XM-18 3 in M390. This year I have EDCed it far more than any other knife I own, just picked it up around Christmas. My first M390 was a Kershaw Link 1870BLKBW that I carried from around the 4th of July 2020 for most of the year.

Not disappointed in either of these knives.

kootenay joe wrote: ↑Tue Apr 13, 2021 3:35 pm old4570, excellent work on your part to make such an informative post. Thank you.
The 'dip' in the blade profile is what is called a "recurve" and is seen on many knives. I do not understand the purpose of a recurve profile and it does make sharpening more difficult.
I am surprised to learn that the M390 steel blade is so soft when you sharpen it. And why it cannot cut paper but does cut flesh and rope i also do not understand. It could be that paper requires a more polished smooth edge whereas other materials are more easily cut with a more 'toothy' edge ?
Would be helpful to hear from others who specialize in blade sharpening as they might be able to explain your findings.
kj

Hardness I cant speak for !
But as for the paper , it is a course edge . Think Ginsu .. Paper is compressed fibre , so the course edge catches the fibre .
And as the edge wears ( becomes more blunt ) , it catches those fibres even better . But , it is still a sharp edge that cuts other materials really well . Like flesh ( dead or alive ) , rope , cardboard and such .
So for what ever reason , this knife steel really likes that edge .
I have another M390 from TwoSun on the way as well another D2 . So we will see what happens .
I posted a video somewhere of the ground edge and what it looks like under magnification .



Remember - Magnification is over 100x ( You can see how course flat polished steel looks like in the video )