20cv, m390...how hard to sharpen?

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kane22

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Feb 25, 2013
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My next knife was going to be in 20cv but now I'm having second thought not knowing if I'll be able to get a good edge back on it. I know there is a trade off, you're not going to get a knife that holds a good edge forever and is real easy to sharpen also. I don't care if it takes a little longer but if I don't have the skill to bring it back that's going to be a problem.

I'm not a sharpening guru like some on here. I normally use a lansky and most of my knives are 154cm. Any help you guys could give would be great!
 
Which Lansky system are you using? If it is the one with diamond stones it shouldn't make much difference. Diamonds cut through all steels pretty easily.

At any rate 20CV is Latrobes version of Bohlers M390. It has a pretty high carbide volume. I don't find it as low in grindability as S90V. I wouldn't let it intimidate you. If it comes with a decent edge, or once you take the time to put your own on, you can maintain it pretty easily with a tertiary bevel (micro bevel).
 
I sharpened a GSO 4.1 in M390 yesterday on a 1x30 and it went very well.
I was expecting it to be stubborn but that was not the case.
Two passes with a worn 400 grit belt formed a small even burr.
Two more passes with a 800 grit and a few with a loaded leather belt and it is beyond screaming sharp.
I've had trouble with lesser steels so I don't know if I got lucky and hit it just right or what but it was a breeze.
 
Steel130 said:
Which Lansky system are you using? If it is the one with diamond stones it shouldn't make much difference. Diamonds cut through all steels pretty easily.

At any rate 20CV is Latrobes version of Bohlers M390. It has a pretty high carbide volume. I don't find it as low in grindability as S90V. I wouldn't let it intimidate you. If it comes with a decent edge, or once you take the time to put your own on, you can maintain it pretty easily with a tertiary bevel (micro bevel).
Click to expand...

My lansky came with course, med, and fine stones. I also bought the ultra fine ceramic stone, but no diamond.
 
kane22 said:
My lansky came with course, med, and fine stones. I also bought the ultra fine ceramic stone, but no diamond.
Click to expand...

I honestly think you will be ok. I don't find M390 to sharpen up much harder than S30V. Honestly it isn't really that these steel are "harder" to sharpen. The more wear resistance they have just means they will take more time.
 
Be patient. I did my BM 480-1 on my Lansky. I'm fairly certain that the process ruined my coarse stone, as I got bored and began applying a LOT of force. Eventually, I sent the knife to Knifenut1013 and paid him to mirror the edge, as I just don't have that kind of free time.
 
From my experience, 20cv is quite time consuming to sharpen. It burrs ups just fine and takes a nice edge, but it just takes FOREVER. I thought I would reprofile a new folder from about 22-24 to 18 degrees and I spend several hours working on it with diamond hones. It got razor sharp, I just had to be very patient. My advise is to take your time and not rush it, it will get there eventually. I had to do it in stages because I was getting frustrated. On the flip side....it holds an edge for a long time!
 
With the proper skill and equipment, they are not hard to sharpen at all. What many people have a hard time with is when they have the wrong tools for the job. Sharpening requires patience and practice to build up your skill level. If a person has no patience, they better have money to send their knives to be sharpened by someone that does have it. ;)
 
Last week I put a very nice edge on my 0777M390. Had to reprofile the blade to 20 degrees (40 inclusive), and had to resort to the 120 grit stone for a while to get that initial burr, but otherwise, it went slick and smooth. I'm using an Edge Pro, but I have that same Lansky set. Once you get the profile set to where you want it, M390 isn't bad at all.

Don't do this at home, folks, but I was whittling a piece of 7075-T6 aluminum with my 0777 last night. It'll do it, but I think it dulls the blade a little.
 
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