Too thin for the job at hand ( most real sharp edges are if you apply side forces) or a burr which is always going to be weak and eventually break off or bend over. At high hardness's usually break.
That may be too blunt an answer but it's going to be found in these two things.
There isn't near enough information for us to really diagnose anything. The edge does look resharpened and not factory so I'm going on that.
How familiar are you with using and sharpening high hardness high carbide steels?
I have had my Endela K390 for almost a year. Is has gone through a kitchen remodel and HVAC replacement. On the remodel, I cut almost everything with it. Cleaned up copper lines. Shaved some hardwood floor splints for refinishing. The only damage it took to the edge was cutting through some old mastic and tape replacing the old HVAC unit.
I will say, it finishes really well. It has a nice crisp edge and I prefer sharpening it to something like the 20Cv class.
The only thing that keeps me from not carrying it more often is the rust. I try not to worry about it too much. I do occasionally cut into some meat bags for grilling. Wash it off. Then worry about if I got all the water off near the scales. It is a minor thing for me, but it has led me to some of the more well rounded steals. I love the edge I can get from it, but these days I am on a SPY27 kick. What it may lack in edge retention, it gets back in that you can keep stropping it for some time to get back to a fine edge.
- Jeff May your feet be warm and dry and your throat warm with whiskey. A knife in hand or in the sock band.
MNOSD Member #0005
Too thin for the job at hand ( most real sharp edges are if you apply side forces) or a burr which is always going to be weak and eventually break off or bend over. At high hardness's usually break.
That may be too blunt an answer but it's going to be found in these two things.
There isn't near enough information for us to really diagnose anything. The edge does look resharpened and not factory so I'm going on that.
How familiar are you with using and sharpening high hardness high carbide steels?
Joe
I use Maxamet and S110V a lot. I also have resharpened S90V and ZDP-189 (chromium carbides tho) several times. I'm used to sharpening these steels.
The factory edge had to be sharpened over because it didn't hold any sort of an edge for longer than a day (and without any bad move from me). I did put a 400 grit edge, with the burr reduced on ceramic and then a 5 micron diamond strop.
I think it's simply the thin stock with a 15 dps edge that was too fragile for the job. It just surprises me a little since I've been able to do the same task at home with my S110V N5 LW this morning (7 am here). Only difference here is a much higher blade and a 3mm bladestock, so that must be what happened.
JSumm wrote:
I have had my Endela K390 for almost a year. Is has gone through a kitchen remodel and HVAC replacement. On the remodel, I cut almost everything with it. Cleaned up copper lines. Shaved some hardwood floor splints for refinishing. The only damage it took to the edge was cutting through some old mastic and tape replacing the old HVAC unit.
[...] What it may lack in edge retention, it gets back in that you can keep stropping it for some time to get back to a fine edge.
I'll compare with my K390 Stretch 2 (received yesterday lol) to see if it is able to achieve such a task.
In the collection : Lots of different steels, in lots of different (and same) Spydercos.
Robin. Finally made an IG : ramo_knives MNOSD member 004* aka Mr. N5s
Too thin for the job at hand ( most real sharp edges are if you apply side forces) or a burr which is always going to be weak and eventually break off or bend over. At high hardness's usually break.
That may be too blunt an answer but it's going to be found in these two things.
There isn't near enough information for us to really diagnose anything. The edge does look resharpened and not factory so I'm going on that.
How familiar are you with using and sharpening high hardness high carbide steels?
Joe
I use Maxamet and S110V a lot. I also have resharpened S90V and ZDP-189 (chromium carbides tho) several times. I'm used to sharpening these steels.
The factory edge had to be sharpened over because it didn't hold any sort of an edge for longer than a day (and without any bad move from me). I did put a 400 grit edge, with the burr reduced on ceramic and then a 5 micron diamond strop.
I think it's simply the thin stock with a 15 dps edge that was too fragile for the job. It just surprises me a little since I've been able to do the same task at home with my S110V N5 LW this morning (7 am here). Only difference here is a much higher blade and a 3mm bladestock, so that must be what happened.
JSumm wrote:
I have had my Endela K390 for almost a year. Is has gone through a kitchen remodel and HVAC replacement. On the remodel, I cut almost everything with it. Cleaned up copper lines. Shaved some hardwood floor splints for refinishing. The only damage it took to the edge was cutting through some old mastic and tape replacing the old HVAC unit.
[...] What it may lack in edge retention, it gets back in that you can keep stropping it for some time to get back to a fine edge.
I'll compare with my K390 Stretch 2 (received yesterday lol) to see if it is able to achieve such a task.
I used my Venev stones, and I think that my F240 is around 400 grit. I did a progression between F100 / F150 and F240 before the burr removal on the ceramic and the stropping.
In the collection : Lots of different steels, in lots of different (and same) Spydercos.
Robin. Finally made an IG : ramo_knives MNOSD member 004* aka Mr. N5s
I use Maxamet and S110V a lot. I also have resharpened S90V and ZDP-189 (chromium carbides tho) several times. I'm used to sharpening these steels.
The factory edge had to be sharpened over because it didn't hold any sort of an edge for longer than a day (and without any bad move from me). I did put a 400 grit edge, with the burr reduced on ceramic and then a 5 micron diamond strop.
I think it's simply the thin stock with a 15 dps edge that was too fragile for the job. It just surprises me a little since I've been able to do the same task at home with my S110V N5 LW this morning (7 am here). Only difference here is a much higher blade and a 3mm bladestock, so that must be what happened.
Maxamet would compare best. The S110 might also be 3 to 4 points less hard depending. These steels are pretty strong ( note I don't mean tough, that is something else entirely) until lateral forces are encountered. At rc 65 ( probably what your K390 is) it is more likely to do exactly what yours did. At rc59 or 60 it might have bent, but still maybe not.
I love K390 now that I have gotten used to it. I have gotten to treat every steel/heat treat knife differently and always avoid the weaknesses which they all have and take advantage of the strengths, of which they all have as well.