Sharpening CPM440V?

sph3ric pyramid

sph3ric pyramid

Joined
Jul 24, 2002
Messages
861
Just wondering if anyone's had success in sharpening this steel to a hair-popping edge.

I've been working at the edge for a while, and the best I can get is hair-scraping; it doesn't push cut all too well, although it slices just fine. Very frustrating, I might just have to convex the edge. I'd prefer to keep the edge bevels, though, because it's easier to touch-up on the Sharpmaker.
 
I get my Millie scary sharp using a lansky. I do meduim then fine stone at 25 deg then a few light swipes at 30 deg on the medium again to take off the wire edge. I then maintain with a diamond stone (ez-lap) for a few weeks before another session on the lansky.

I've noticed the hair popping property of the edge doesn't last that long but the knife stays very sharp for most day to day cutting for ages before needing a touch up.

One property of this knife is how it seems to invalidate my previous measures of sharpness. Long after it won't shave or easily slice paper it still cuts with ease (rope, tape, fish heads etc.
 
Got a gunting hair-popping sharp by using the edgepro, then stropping to a semi mirror finish. you shouldn't have a problem getting it hair-popping sharp. if you're using the sharpmaker, I don't think you can achieve that w/o hours n hours n hours of elbow grease.
 
The steel sruture does not let it take a really fine edge.But I can get it very sharp by useing only the first 2 steps on the brown stones of my 204 and stropeing it on blue jeans.
 
I can get it very sharp, but not quite hair-shaving. Maybe it is a property of the steel? When I polish the edge, I find it won't grab on anything, and thus won't slice paper until I find the right angle. Never had a problem with that with any other steel,

Can anyone say a bit more about the type of edge can be acheived with this steel? It seems to sharpen like D2.
 
When I say very sharp I mean I can get it to the shaveing arm hair with ease and sliceing paper point.I really don't try to go further because this is as sharp as I want it.If I use the white stones it goes from shaveing sharp to not hardly cutting any hair so I just stop useing the whites on CPM steels.BTW I sharpen it on 30 degrees only.
 
Originally posted by sph3ric pyramid
I can get it very sharp, but not quite hair-shaving. Maybe it is a property of the steel?
Click to expand...
The 440V knives I've had or still do own are all Spyderco's, well, and one Kershaw. All had a heat treat that allowed quite a nice edge, not matter how far down I took them in "grit". I usually stop at a fine diamond for a grabby, toothy working edge, but even the toothy edge will cleanly shave the coarse hair on my legs, and the finer hair on my arms quite well... not scrapey, cleanly.

I don't think it's a steel thing... it's either a technique thing or you got a mediocre heat treat. Probably technique, and probably not getting the burr cut off or stropped off cleanly.
 
I can get my Military to pop hair without a lot of trouble. If the knife is dull, I start with a coarse DMT. I then go directly to the white Sharpmaker stones and strop if desired. The Military cuts better with a more micro-serrated edge than a polished edge.
 
How real is the need to cut off the burr? Haven't any experience with the CPM series, and have never seen a steel that's needed that.
 
I used the whites of my 204 to obtain a shaving sharp edge both for my Earth Native and Chinook. No problems.
 
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