How to get 440C knife razor sharp

R

ronie1988

Joined
May 25, 2014
Messages
168
Hi, I have SmithPP1 and high grit stone with me....My 440A and 1095 gets razor sharp on them but My KM2000 in N695 or 440C doesn't gets Razor edge. Can I get one without changing grind angle?
 
Something doesn't sound right. 440a is a worse steel then 440c. What brand knife? What angle? What grit is high grit stone?
 
Also isn't smith pp a carbide sharpener on the coarse side? If so that's your problem. Those things tear up edges.
 
I am just using ceramic part of PP.....My 440A is Ontario Mk3, 1095 is Glock81 and N695/440C is Eickhorn KM2000
 
Something doesn't sound right. 440a is a worse steel then 440c.
Click to expand...

How is it worse? Do you mean lower carbide percentage? Less edge retention? Tougher? Easier to sharpen? Higher edge stability? All of the above are true statements. Nothing is wrong with 440A. It's just a different steel from 440C just like Aus 6 is different from aus 8, whis are both different from aus 10, which are all different from 1095, and all are... you get the idea.

440C is known for it's blocky carbide structure and large grain. It can certainly take a sharp edge but will never be like a razor blade steel. What you need is something that will cut through the carbides. Keep your synthetic stone clean and I'm pretty sure any of them can do that. Good technique can get most anything sharp. I saw enough of that in my career as a prison guard.

440C is probably my least favorite steel and though I don't really like it I still respect what it will do, and won't do just like all the other steels out there. They are all good at what they are designed for. If they are also good at other things it's great, but not necessarily on purpose. If you don't like 440C than like me, get other steels that suit you more.

It has pretty decent wear resistance and great corrosion resistance. As I stated before it isn't all that fine grained and it isn't tough, even for a stainless especially compared to more modern powder steels.

Similar attributes but better edge would be something like 154cm. Aus 10 is almost 440C but designed to have a bit better grain structure. It's slightly tougher and has a more stable edge with similar corrosion resistance and wear resistance.

joe
 
Last edited:
+1 to Joe's comments^^ about 440A vs 440C. There's absolutely nothing wrong with 440A, and nothing 'worse' about it; in fact, it's simpler makeup makes it easy to get razor sharp, assuming the heat treat is good. It's less wear-resistant than 440C, but that isn't 'worse'; it's only as it's designed. The lower wear-resistance is due to fewer and/or smaller carbides in the alloy; that's also the thing that'll make it easier to refine to a very fine razor edge. The ease of sharpening and finer grain of 440A will actually make it 'better than' 440C in this specific regard (440A will also have better corrosion resistance); it's a matter of which attributes one prefers in a given steel. There's almost always some trade-off between ease of sharpening and high wear-resistance; increasing one attribute will usually be at the slight detriment of the other.

440C's higher chromium carbide content makes it more challenging to sharpen on lesser abrasives, like Arkansas stones for example. On the other hand, silicon carbide will eat it for breakfast. A combination of thinning the edge grind and using such an abrasive for finishing & polishing 440C can make it much easier to put a razor edge on it. 440C responds very well to high-grit finishing on SiC wet/dry sandpaper (to 1000+ grit levels), and stropping with some aggressive aluminum oxide compound will take it further, and maintain it easily. I have an older Buck 112 in 440C, and the above is how I thinned it, convexed it and polished it. Occasional stropping on firmly-backed denim with some white rouge (AlOx) or slightly coarser grey AlOx Sears #2 compound has worked very well to keep it hair-popping.


David
 
Last edited:
ronie1988 said:
I am just using ceramic part of PP.....My 440A is Ontario Mk3, 1095 is Glock81 and N695/440C is Eickhorn KM2000
Click to expand...

If your edge is significantly dull, the tiny ceramic inserts in your PP (Pocket Pal?) sharpener won't be aggressive enough to do much; and even less-so, if the ceramics are heavily loaded with swarf from multiple uses. Most pull-through sharpeners also use a pretty wide edge angle setting; that won't help the effort at all, in making a dull edge razor-sharp. Assuming your 'high grit stone' (as mentioned in your first post) is even finer than the PP's ceramic, no help there either.

Per my last post, try some more aggressive (coarser) abrasives, in either aluminum oxide or silicon carbide, or diamond. Norton has good options in the SiC ('Crystolon') or AlOx ('India'), or you could just use some wet/dry sandpaper in either of SiC or AlOx; both 3M and Norton are good brands for those.


David
 
Last edited:
Obsessed with Edges said:
If your edge is significantly dull, the tiny ceramic inserts in your PP (Pocket Pal?) sharpener won't be aggressive enough to do much; and even less-so, if the ceramics are heavily loaded with swarf from multiple uses. Most pull-through sharpeners also use a pretty wide edge angle setting; that won't help the effort at all, in making a dull edge razor-sharp. Assuming your 'high grit stone' (as mentioned in your first post) is even finer than the PP's ceramic, no help there either.

Per my last post, try some more aggressive (coarser) abrasives, in either aluminum oxide or silicon carbide, or diamond. Norton has good options in the SiC ('Crystolon') or AlOx ('India'), or you could just use some wet/dry sandpaper in either of SiC or AlOx; both 3M and Norton are good brands for those.


David
Click to expand...

If I use coarser abrasive like the diamond one provided on Eickhorn sheath then will it develop smooth and sharp edge? or will it give me rough notchy edge?? I am very new to knife sharpening
 
ronie1988 said:
If I use coarser abrasive like the diamond one provided on Eickhorn sheath then will it develop smooth and sharp edge? or will it give me rough notchy edge?? I am very new to knife sharpening
Click to expand...

Diamond sharpeners will generally leave a 'toothy' edge, though it can be very sharp with good technique; that would mean using light pressure, then finishing with very, very light passes. The diamond hone can very quickly make the apex of the edge crisp again, which is likely what you need most right now; if you want a finer finish beyond that, then finish with your higher grit stone to clean up the coarse scratch pattern.


David
 
Yes, with 440C one must spend more time on the correct stone. A high grit SiC stone or India then on to a Spyderco ceramic. This will give you a very sharp edge.
Work on your techique with it. This steel is a very good steel. DM
 
You should be able to get both steels exactly as sharp as each other. This sounds to me like someone is not cleanly apexing and/or removing burrs.
 
I had excellent results with 440C (BuckLite) on a Chosera 800 once the factory edge was removed and fresh steel available. Before that probably fatigued steel by factory buffering. After the 800 only a few very light edge trailing strokes on the 2k and deburring on the same.
 
You must log in or register to reply here.
Back
Top