Sharpening angle for M390

Cursum Perficio

Cursum Perficio

Joined
Oct 27, 2012
Messages
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Greetings :)
I've developed an interest in folding knives and the sharpening thereof.
I had zero knife sharpening skills, so I bought a wicked edge, including 800/1000 stones, 1200/1600 ceramics and strops.
I'm quite happy with the edge I've put on my AUS8 SOG Aegis, did it at 20'/side.
My S30V Benchmade Subrosa was sharp out of the box but half of the edge had tiny chips along it. Went for 19'/side and patiently worked away at it on the WE until it was all smooth and nice and sharp - to me at least.

Now I'm looking at my new Benchmade Barrage 581. I really like this knife, and want to put a really sharp cutting edge on it but I'm unsure what angle to use for this M390 blade. Would like it to be really sharp. It will be carried and see light to medium use, though to be honest it will be also used to show off how sharp I can make a knife.
Any advice or suggestions on what angle to sharpen it at, or advice on M390 sharpening generally, would be greatly appreciated.
 
M390 sharpens up nicely and with little fuss. If you want to "show off" how sharp your knife is, a narrower angle is always better. However, you will trade off some edge durability as the angle decreases. 15 deg/side will work great for light to medium use. The "wow" factor for sharpness really goes up (for me at least) at angles of 12 deg/side or less.

Enjoy the 581...it is a great slicer in a fantastic steel.
 
on my CPM154 blade EDC folder, i did 35 degrees inclusive with my WE, and it's by FAR the sharpest i've ever gotten a knife

M390 should be able to hold up perfectly well up down to 30 degrees.

*edit: Honestly, if you are REALLY patient with your WE, you can get hair popping edges at 40degrees inclusive. I don't see any reason to go below 30 unless you're sharpening a kitchen knife.
 
OK, thanks for replies. Was thinking 19-18 deg per side, now I feel encouraged to go sharper.
I'm prepared to lose a bit in edge retention on this blade to get 'damn that's sharp'.
 
I was running a no name Japanese made knife at 7 degrees per side with no trouble, but it was very thin. Trying that on a benchmade would likely yield bevels that are unacceptably wide. It took cutting metal to damage the edge.

Since you have a Wicked Edge, try this. Start at 20 degrees per side (dps) and lower the angle a couple degrees each time you sharpen. Next time try 17 dps, then 14, and so on. If the edge starts to get damaged, go back up to the last setting and add a microbevel. I'm currently using an old cold steel knife with a 12 degree bevel per side, and a 15 degree microbevel off the Sharpmaker. No damage so far, even chopping small branches in the yard. I might even move down to a 7 dps edge with a 10 dps microbevel, but this knife gets used to cut bones sometimes, so maybe not.

Also, edge angle has little to do with sharpness. There are members here that report hair whittling edges at 27 degrees per side. Lower angle edges cut better, but you can get them all ridiculously sharp.
 
"light"everyday use can accept angles less than 15°/side no problem. BUT it won't forgive anything. i mean, if you drop a knife edge first on the floor ( it happens !) the damages with a 20dps edge and 10dps will be very different. if you find a metal staple on cardboard too etc .... a knife with very thin bevels will stand to most cutting uses, you just have to be more carefull.

all this assuming the steel itself can hold the angle without failling. m390 in particular behaves quite well below 15°/sidefrom my experience with spydercos.
 
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Thanks for all replies, really appreciate the input.
I never thought knife sharpening could be so interesting, but thanks to the WE I'm really enjoying this new hobby :)
 
I'd really like to try a Wicked Edge or Edge Pro. The angle control would give me the ability to try some things and be sure at least that variable was removed. What's the lowest angle the WE can handle?
 
me2 said:
I'd really like to try a Wicked Edge or Edge Pro. The angle control would give me the ability to try some things and be sure at least that variable was removed. What's the lowest angle the WE can handle?
Click to expand...

The standard WE I have can go down to 15 dps. Add the upgrade kit with the riser block and it can go less though I dont know how much less.
At the steeper angles I find the stones can get close to the clamp, so the blade needs to be clamped with the edge higher above the clamp.
Also, it does take the upgraded WE and the angle cube to really be precise with angles.

For what it's worth the WE isn't cheap, but I'm real happy I bought it.
 
I got a hair popping 41 degree inclusive edge on my W49 bowie sharpening it freehand. A WE system could do the same for sure (not sure if they can make 41 degree inclusive edges, but you get the idea)

Welcome to the forums,
Connor
 
how did you measure 41 inclusive on a freehand bevel, thats a pretty precise measure.
 
SusAntigoon said:
That's holding the knife at a 20.5 angle... I don't think I could even see the difference of half a degree.
Click to expand...

Using a vice to hold the blade, a nice light, an eye loupe, and a Starrett C-19 protactor. It took me a few minutes to secure the materials and set it all up, but the thick blade means a wide bevel, so measuring was quick

Connor
 
Unfortunately, you can't get below 15 degrees on the WEPS.

I'd suggest 15 degrees with a 17.5 degree secondary bevel.
 
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