Sharpening CPM440V

F

FullerH

Joined
Nov 25, 1998
Messages
12,632
I have 3 440V blabes and am giving another 2 to friends. Now, I have not needed to sharpen any of mine even though I have used the H**l out of my BF Native, even to openning a lots of boxes, and it still shaves easily! But I know that I will eventually need to sharpen it, and I will need to suggest to my friends how to go about it, so, are there any suggestions beyond the usual Sharpmaker? Steven Dick suggests teh Chef's Choice sharpener in his bok on the practical folding knife. I have been told not to try to over sharpen it, as the steel needs to be "toothy" with its carbides. Thanks in advance.

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Walk in the Light,
Hugh Fuller
 
Read the FAQs on BladeForums for a start.

Then visit Razor Edge Systems on the Web. Maybe get yourself a copy of the book (on that site) "The Razor Edge Book of Sharpening".

Other than that, just practise and see what works for YOU!
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Heyns, I am sorry, I should have mentioned that I do know how to sharpen a normal knife and that doing so has no intimidation for me. I did go back and reread the FAQs on sharpening and saw nothing on CPM440V, which is why I had asked the question in the first place.

I have been given to understand that 440V is different from other steels in that it needs to be sharpened in a different way. What I am seeking to ascertain is whether or not that is true and, if so, just how to go about sharpening a CPM440V blade. As an example, one story that I heard is that one should not try to put too fine an edge on a 440V blade; this seems not to make sense since Spyderco sells them with a scary finely sharp blade in their StarMate, Military, and new Native.

Again, any assistance in this would be appreciated.

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Walk in the Light,
Hugh Fuller
 
Spyderco sells them with a scary finely sharp blade in their StarMate, Military, and new Native
Click to expand...

True, but like the Buck Edge2000 with its narrow included edge angle (like Spyderco), they may just be trying for a nice "out of box" experience for the buyer.

Having a shaving sharp knife out of the box doesn't mean it's recommended that you maintain it that way. OTOH, if your knives have been working well for you "out of the box", then maybe you should keep the same angle.

I think several of us managed to dent or roll the edge on the 440V Native when we struck a hard object (ie, the infamous staple test). If you don't anticipate doing the same on a regular basis, you may well want to keep the narrow edge grind to get that satisfying cut thru paper and such.

People who want to punch thru cans and car doors may want to choose a less aggressive angle. The finer (ie narrower angle) edge you put on the blade, the weaker it'll be when put to task against an immovable object, tho it'll cut paper like sin
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Hugh,

I read an article that to get 440V really sharp you need to use a diamond hone. Also, the writer recommended that you not allow the blade to get too dull because it makes it harder to sharpen. Some have stated they get good results using their Sharpmaker. As for using the Chef's Choice, if this is the electric sharpener, I wouldn't do it. It changes the bevel and can remove too much steel. Great for most kitchen stuff but not for our valued pocket/hunting knives.

Dave
 
I have a 440V fixed which takes a very sharp, crisp edge w/fine ceramic stones a la Sharpmaker. I really like the 440V and haven't (yet?) had the problems mentioned by others. I don't think it requires any special technique.

When you do sharpen it, try out what you normally do. If you don't get a decent edge, let us all know what the problem is, and maybe we can figure out any "special approaches" then. My guess is you'll get a great edge.

Glen
 
That's a really good question, Fuller. I'm hesitant to respond because I really don't have much experience sharpening 440-V. Like you said, you just don't have to sharpen it very often!

From what little experience I do have, it seems that stropping may not be beneficial to the performance of the edge. If you sharpen with a fine stone, and leave it at that, the edge cuts in that weird "toothy" way. When you polish the edge, it kind of slides rather than cuts. The difference is very small though: in fact, the difference is so difficult to perceive that I may be hallucinating it, but I don't think so.

I have heard that repeated steeling of the edge is also not beneficial. I have no experience with this, but it sounds reasonable. The theory is that steeling would work for a while, but at some point the edge should be ground down a bit to expose more carbides. I think Cliff Stamp talked about this somewhere, but I'm not sure.

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Cerulean

"Just because some folks think you make great kydex sheaths doesn't make you into some sort of mind reading psychologist." -Paracelsus
 
Hugh - CPM-440V is a very new steel for production knives. There is much opinion, but little real experience. Much of the "facts & figures" are from laboratory testing.

I would recommend sharpening your CPM knives as you would any other. The Sharpmaker works just fine. I keep my plain edge Military at a 30 degree angle as I'm "testing" always". My serrateed Military I maintain at a 40 degree inclusive angle.

I would not recommend any power sharpener, Power grinders are very quick and some skill is necessary to avoid removing too much material. You don't want to remove any more steel than is necessary to restore the edge you like.

sal
 
I have a 440V Military, BF Native and Starmate, and have sharpened them all with an Edgepro Apex. I put a really smooth mirror finish, and haven't had any problems, and they're VERY sharp; I also haven't had any edge chipping problems. I would say the angle is roughly 21-23 degrees.

I found that 440V isn't that hard to sharpen, taking only a slightly longer time than ATS-34. M-2, on the other hand, I found to be a pain in the arse...go figure..

--dan
 
I also use an Apex at 21 degrees with a mirror polish on my 440V steels and I've had no problems at all. VERY SHARP!

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"Better to reign in Hell, than serve in Heav'n"
John Milton
There are only two types of people; those who understand this, and those who think they do.
 
I thank you all. Sal, I had suspected what you said; more opinion than fact. Thanks for the heads-up on powered machinery. I generally use Arkansas stones, myself, as that is what I grew up using and what I am most comfortable using.

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Walk in the Light,
Hugh Fuller
 
I gave my friend his Native today, so I am bringing this BTTT for his sake.

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Walk in the Light,
Hugh Fuller
 
Razor Edge Systems, Inc
www.razoredgesystems.com
The Razor Edge Book of Sharpening is available at our website.
Also, check out our latest product release--The Mousetrap Steel. With the Mousetrap Steel, you will be able to bring back your sharpest edge with a few strokes.
The Mousetrap steel has been used in the meat and poultry industry for over 15 years.
 
Hi RazorEdge. Welcome to the Spyderco forum. Whom do we have the honor of speaking to?

Your "Mouse trap" steel has come up in conversation here several times. Please give my best to John.

sal
 
Hugh,
Just a few strokes on the fine rods on the sharpmaker always gives me a scary sharp edge. Just don't let t get to dull beforehand.
Bill
 
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