Performance characteristics

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Mephtyrm

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Jan 23, 2011
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I have a Ganzo G704 that says 440C on the blade, and I have found that it does noticeably takes longer to sharpen it.
Since it is a fairly thick blade, I put a 17 degree angle on it with my Lanksy then preded to freehand a 23 microbevel on it.
I did a few cardboard cutting tests to see if the edge retention was noticeable different, and it does seem to hold
a 750 grit edge polished to 8000 grit on a DMT XX Fine then stropped on bare leather belts longer than my AUS-8(A), 8Cr13MoV, and 14cn28 noticeably longer.
At least in terms of wearing, though. After going through a few sheets of cardboard, the edge had several tiny catches throughout the edge.
The steels above were noticeably less keen, but they had little to no catches at all compared to the 440C.

I've heard about how 440C isn't known mainly for taking a fine edge and also holding it, so is it heat treat, edge geometry, or just
how 440C works and I'm too used to what I consider "Modern day 1095" steels?
 
440C is good steel for a knife, certainly comparable IMO to Aus8, another good, middle of the road steel.
 
440C can and will take & hold a very fine edge. Among the best examples are Buck's older knives made from it. Collectors of Buck's older, classic line of knives consider it the best steel Buck has used in regular production knives. Used to be a favorite among custom makers too, for good reason.

As with any steel, the heat-treatment can make it look very good, or horrible.
 
In my experience a good 440c is much better than 8cr and Aus8. My 440c from Bench made is actually quite easy to put an ultra fine edge on. 440c gets a bad rap, but its not the lowly steel everyone thinks it is. In my world its just only slightly less good than 154cm. IMHO.
 
Mephtyrm said:
I have a Ganzo G704 that says 440C on the blade, and I have found that it does noticeably takes longer to sharpen it.
Since it is a fairly thick blade, I put a 17 degree angle on it with my Lanksy then preded to freehand a 23 microbevel on it.
I did a few cardboard cutting tests to see if the edge retention was noticeable different, and it does seem to hold
a 750 grit edge polished to 8000 grit on a DMT XX Fine then stropped on bare leather belts longer than my AUS-8(A), 8Cr13MoV, and 14cn28 noticeably longer.
At least in terms of wearing, though. After going through a few sheets of cardboard, the edge had several tiny catches throughout the edge.
The steels above were noticeably less keen, but they had little to no catches at all compared to the 440C.

I've heard about how 440C isn't known mainly for taking a fine edge and also holding it, so is it heat treat, edge geometry, or just
how 440C works and I'm too used to what I consider "Modern day 1095" steels?
Click to expand...

What you are likely noticing with the "catches" are the carbides in the 440C. Think of the aggregate in concrete vs. the lack of it in pure cement and you will get the idea.

Neither AUS-8, nor 8Cr13MoV, nor 14C28N form significant amounts of carbides. They don't have enough carbon. They are like cement: very fine and smooth, but have less abrasion resistance.

440C does form large carbides. It is like concrete: Not as fine, but the aggregate gives it better abrasion resistance.

It is possible to give all the alloys you mention the same fine edge, though it will probably take more work with 440C, as you will have to grind the chromium carbides smooth. Once the blades are in use, and the alloys all start wearing, the carbides in the 440C will start protruding from the surface of the blade, just as the aggregate in concrete will. The steel around them gets worn away and the carbides are left. Once the carbides start protruding, the 440C will have a toothier edge than the other alloys, but will keep on cutting. The other alloys will just wear away to dullness.

In my testing, which is based on making slicing cuts in manila rope and looking for edge damage under a hand lens, I found that 440C held an edge noticeably longer than AUS-8, 8Cr13MoV, or 14C28N. 440C holds an edge a bit less well than 154CM or VG10. The difference between AUS8 and 440C is greater than the difference between 440C and 154CM.

As for 1095, given good heat treating of both alloys, 1095 has about the same edge retention as AUS8. And both take a nice fine edge. I consider AUS8 to be stainless 1095 as far as edge retention goes.
 
The question is, whether Ganzo uses real 440C. I have Navy k631 that's also stamped 440C. The edge holding is being tested by daily use, but given the different grind & profile, I'm afraid it won't be conclusive enough against 8Cr13MoV of the Sanrenmu & Enlan I have. Another factor is Enlan heat treatment result in higher RC (57-59) while Sanrenmu published 56-58. No documentation about Navy or Ganzo.

I don't want this to be 'bash chinese knives' thread, but to inquire further if they do use 440C. IIRC, earlier Spyderco incoming batch from China (Byrd?) were labelled 440C but they turned out not to be the case, it was the 8Cr13MoV series (7, 8 or 9, am not sure).
 
Boker has spec'd many of their stainless traditionals as 440C. I have to believe they don't take it as high in RC as other makes do. I have a stag-handled 'camp knife' (like a Scout pattern) from Boker, and when I sharpened it up, it reminded me almost exactly of the stainless used in Victorinox's SAKs. Took a very fine shaving edge, very easily and quick. My older Buck 112 in 440C (a '2-dot' model, dating from around 1980 or so), seems much harder. I've had that knife for a very long time, and it was stored away because I was never able to sharpen it properly. Fast-forward to a couple years ago, and I finally figured that out. Convexed it on wet/dry paper to ~2000+ finish, and it's now one of my favorites.

And 8Cr13MoV is pretty good stuff too. In terms of the elemental makeup, it's very similar to AUS-8. I have a total of 13 knives made from it, all from A.G. Russell. His quality standards are as high as can be, and these blades were all taken to ~57-58 RC. I've put new bevels on at least 4 of them (they didn't need it, but I wanted to see what the steel was capable of). Sharpened up excellently, to very fine edges that seem to hold well. I like this steel, especially at the price point.
 
David,

I don't doubt 8Cr13MoV capability, been using them a lot. However, from the discussion, it seems that 440C has carbides that differentiate the characteristic. Saying it's 440C but actually 8Cr family is misleading IMHO.
 
Chris "Anagarika";10589957 said:
David,

I don't doubt 8Cr13MoV capability, been using them a lot. However, from the discussion, it seems that 440C has carbides that differentiate the characteristic. Saying it's 440C but actually 8Cr family is misleading IMHO.
Click to expand...

Agreed. That would be misleading indeed.
 
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