Sharpening M390

R

Reediculos

Joined
Dec 4, 2013
Messages
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Hey Guys,

Anyone re-profiled M390 to a 25 or even 20 degree blade angle, how long/well has it held an edge afterwards?

I just got a 586 is the reason I'm asking, its still factory sharp, but it could always be a little sharper...
 
Reediculos said:
Hey Guys,

Anyone re-profiled M390 to a 25 or even 20 degree blade angle, how long/well has it held an edge afterwards?

I just got a 586 is the reason I'm asking, its still factory sharp, but it could always be a little sharper...
Click to expand...

Inclusive? Holy crap that scares me even thinking about it. I'd love to see pics if someone has laid back an edge this far.
 
What kind of angle does the 586 have from the factory? I've got a 710 in M390 and it came about 28 from Benchmade and holds the edge like nothing I've ever seen.
 
jkarp_53 said:
Sharpening is done by hand, their average edge is 24 degrees inclusive.
Click to expand...

24º per side, maybe? Surely not 24º inclusive; that would be insanely low for a production folder. Most of my BM's seem to have been between ~35º and ~40º though I've had a few over 40º inclusive - can't hit the edge with a sharpmaker.

On the M390 I've taken it down to about 32º inclusive (16º per side) on a 710 and 730 and it's held up well (esp. the 710, did a great job as a hunting knife this year). The flat grind on my 581 seems to cut well enough even with the factory edge angle that I've just been touching it up with a sharpmaker as necessary and haven't reprofiled that one yet.
 
My 480-1 is around 28 inclusive with a mirrored edge. It cuts like you wouldn't believe, but I definitely don't use it for hard stuff. The edge has remained undamaged and imaculate for over 6 months.
 
I don't have a Benchmade in M390, but I did reprofile my ZT0777 M390 to 19 degrees per side a few months ago. I really only use it for common cutting tasks, but I haven't had to sharpen it again since the initial sharpening.

There's a Wicked Edge ZT0777 video on Youtube where he reprofiled the ZT0777 to 18 or 19 degrees a side and did a lot of cutting tests on cardboard and paper and was still able to shave hair after.
 
Skywalker31 said:
24º per side, maybe? Surely not 24º inclusive; that would be insanely low for a production folder. Most of my BM's seem to have been between ~35º and ~40º though I've had a few over 40º inclusive - can't hit the edge with a sharpmaker.

On the M390 I've taken it down to about 32º inclusive (16º per side) on a 710 and 730 and it's held up well (esp. the 710, did a great job as a hunting knife this year). The flat grind on my 581 seems to cut well enough even with the factory edge angle that I've just been touching it up with a sharpmaker as necessary and haven't reprofiled that one yet.
Click to expand...

Yes I meant on each side. I did send up a 710D2 and asked for 30 inclusive, or 15 on each side, and that knife IS insanely sharp.
 
I bought my dad one of those exclusives with the blue handle and carbon fiber insets with M390 blade. He loves it and uses it a ton. He could not believe how sharp it was from benchmade. He chipped out about 1/4" of the edge hitting something by accident. When I sharpened it I found the edge was very thin. I set it on my diamond stone and just barely angled it up off the thumbstuds to hone and it basically perfectly matched the factory angle. Don't know what this says for an actual number. I will say it was quick and easy to sharpen and it got REALLY REALLY SHARP! I was very impressed with the M390 ease of sharpening. No awful burr forming and hanging on. A few passes on my old hanging strop and he was literally whittling hairs. Not sure how tough M390 is but he cuts boxes a lot with it and really anything. He uses it for everything. So far the only issue was a large chip out from accidental damage.

Kevin
 
I have a BM 7505 with m390 it wasn't bad out of the box but I like to spend my spare time in search of the perfect edge. I set up my wicked edge pro to 16 degrees (per side) and went to work , after some time re-profiling with 200 g diamond I was very impressed how the blade was resisting my effort to change the angle. After some time the edge was ready to work down to 400-600-800-1000 diamonds then the ceramics came out to begin the finish run…once I liked the finish the ceramics did I gave a final strop finish to .5 micron .
The edge is crazy sharp now with a mirror finish that's just right.

As for it holding an edge I haven't cut to much with it but I can say i cut several pieces of 5/8" polydacron rope the other day and it went through it with very little effort and no effect on the edge I can tell.

Bottom line if you work it go with a heavier angle , if you want a hair popping slasher make the angle as fine as you can ...
 
I have a 581 and a 586, both have been to Wicked Edge Land and came away with a polished 17' per side.
They slice, oh boy do they slice.

Was at work recently with a roast chicken and bread for sandwiches. Workmate asks if he can have one and I say yeh sure help yourself. Let him use my 581 to cut the chicken.
Part way through eating his sandwich he's spitting bits of ribcage out of his mouth, and remarked that he hadn't even felt the knife cutting through the bones.
I cleaned the blade and cut some A4 copy paper with it, sure enough I could feel three tiny nicks in the edge catching slightly on the paper. Thanks mate. Ah well, some stroking on the Sharpmaker fine stone smoothed them out.
 
I sharpened a 710 in M390 to 30 degree inclusive on my edge pro 6 months ago. It's seen light use, maybe been carried 50 times since. It can still whittle hair easily.
 
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