Case CV vs Victorinox steels

pinnah said:
Super helpful. Thanks! Interesting thought about the Chromium and burring at low Rc levels. I notice more of a difference between Vic's Inox and Case SS than I do between Opinel's Inox and Buck's 420HC. Weird.
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I notice the same relationships.

There's a very predictable relationship between edge-holding, burring and wire edge issues, when you look at somewhat lower levels of carbon (~0.5%, give or take) and higher chromium (above 13%, more often than not) in the same blade, especially at lower hardness levels. All of the blade steels in which I've noticed issues with burrs and wires all have essentially similar chemistry in that regard. After a while, it's easy to understand why most cutlery steel wouldn't perform acceptably well with anything much below 0.5% carbon content, as the edge-holding really degrades below that threshold. Heat treat can only do so much, as it's largely dependent on there being enough carbon in the steel to be effective. Having said that, once you do get above that minimum threshold for carbon, heat treat makes most of the difference in how a particular edge will perform.

Chromium adds a lot of ductility to steel ('bendy', 'gummy' burrs & wires), which can be offset somewhat by treating to higher RC (best seen in the comparison between Case's 420HC and Buck's, with the only difference being RC hardness), OR by increasing carbon content in relation to the chromium. 440C is a great example: very high chromium at 16-18%, but proportionately higher carbon as well (1.2%), which has much to do with how well it holds an edge, without being too 'gummy' or ductile.


David
 
Obsessed with Edges said:
There's a very predictable relationship between edge-holding, burring and wire edge issues, when you look at somewhat lower levels of carbon (~0.5%, give or take) and higher chromium (above 13%, more often than not) in the same blade, especially at lower hardness levels. All of the blade steels in which I've noticed issues with burrs and wires all have essentially similar chemistry in that regard. After a while, it's easy to understand why most cutlery steel wouldn't perform acceptably well with anything much below 0.5% carbon content, as the edge-holding really degrades below that threshold. Heat treat can only do so much, as it's largely dependent on there being enough carbon in the steel to be effective. Having said that, once you do get above that minimum threshold for carbon, heat treat makes most of the difference in how a particular edge will perform.

Chromium adds a lot of ductility to steel ('bendy', 'gummy' burrs & wires), which can be offset somewhat by treating to higher RC (best seen in the comparison between Case's 420HC and Buck's, with the only difference being RC hardness), OR by increasing carbon content in relation to the chromium. 440C is a great example: very high chromium at 16-18%, but proportionately higher carbon as well (1.2%), which has much to do with how well it holds an edge, without being too 'gummy' or ductile.
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David, this is gold and I'm saving it to my hard drive.

Follow up, if I may... What does this imply imply about 420 J2, which is used by Buck for the imported slip joints?

Here are the numbers I could find on it...
Carbon = 0.15-0.36%
Chromium = 12-14%
Molybdenum = 0%
Vanadium = 0%
Manganese = 1.00%
Silicon = 1.00%

Am I correct in understanding that this is very low in carbon (comparatively) and high in chromium and thus prone to bendy wires and low edge hold?

Also I understand that it is limited in what is possible in terms of Rc (around 52 or 54 Rc max). Would there be any realistic hope that Buck's Chinese sources could push the 420J2 blades to higher Rc levels if they were following a Bos style heat treat? Or does the composition of the 420 J2 sort of leave that steel as unredeemable in that department?
 
pinnah said:
David, this is gold and I'm saving it to my hard drive.

Follow up, if I may... What does this imply imply about 420 J2, which is used by Buck for the imported slip joints?

Here are the numbers I could find on it...
Carbon = 0.15-0.36%
Chromium = 12-14%
Molybdenum = 0%
Vanadium = 0%
Manganese = 1.00%
Silicon = 1.00%

Am I correct in understanding that this is very low in carbon (comparatively) and high in chromium and thus prone to bendy wires and low edge hold?

Also I understand that it is limited in what is possible in terms of Rc (around 52 or 54 Rc max). Would there be any realistic hope that Buck's Chinese sources could push the 420J2 blades to higher Rc levels if they were following a Bos style heat treat? Or does the composition of the 420 J2 sort of leave that steel as unredeemable in that department?
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I still don't understand the logic of using 420J2 for any cutlery at all (save for table knives, maybe). The only other reputable reference I've seen, for using it in knives, is from one U.S. maker who reportedly used it in very flexible blades at lower RC, like fillet knives. Being that the carbon is so low, and the chromium still fairly high, corrosion-resistance is the emphasis there, which is at least somewhat justifiable in a knife made for fishing. Even then, with the current advances in steel and heat-treat processes, there's isn't much reason to not use something better (even 420HC would be a big improvement).

Carbon is what makes hardening possible in steel (by heat treat), to any significantly high RC. So, when carbon content is that low, I have little faith in the steel's ability to hold an edge well at all. I still question whether Chinese sources are actually using 420J2 (in spite of mfrs. saying so), though I wouldn't doubt they might use something of similar chemistry, but of Chinese manufacture. I sometimes have to remind myself that much of the world uses knives made of steels that we'd usually consider vastly inferior (too soft, etc.), but it still serves a purpose for many in the world, otherwise.


David
 
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Made to be purchased, not used. The perfect consumer product.

Sigh.

Thanks for the confirmation.
 
A lot of good info so far! I think the case cv and Vic ss are really close to the same in sharpenability. Both easy to maintain and great to EDC.
 
The beauty of both the Case and Victorinox SAKs are their ease of sharpening. I don't mind touching up an edge once a week. These knives are meant for the general knife user and can be adequately sharpened by most.

Great thread by the way for you folks that are much more informed on the various steel mixes and how those mixes relate to sharpening and edge retention.
 
I thoroughly enjoyed this thread gentlemen. Thanks for sharing your knowledge and insight.

Al
 
mtangent said:
Is Case harder? I gave up on Buck's 420, I'm just trying Case SS now, & find it better.
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Case's stainless is generally known to be somewhat lower in RC, probably somewhere around 56-57 RC. Buck's version is at around 58, give or take. The most significant difference I've seen in use, is just the burring/wire edge cleanup. I've also noticed the slightly harder Buck blades will sharpen up to a slightly finer finish with a given grit (confirms the extra hardness). The slightly higher hardness of Buck's edges seems to make the burrs or wires a little more brittle, therefore easier to thin and break off. Case's burrs/wires are more ductile, so they tend to bend back/forth quite a lot without breaking off. But, having said that, they're still fairly easy to gently abrade away. I like using wet/dry sandpaper in grits from 320 and up, in trailing edge strokes at very light pressure. Follow that with stropping on green compound on leather (I like using sueded leather for this). This works fine for the Buck blades, too. It's just that they'll generally need less burr cleanup off the hones, and whatever they do need will get done much quicker; often in just a handful of passes. Either one is still very easy to get along with, and both will get screaming sharp by relatively simple means. I've even liked the edges I've produced on Case's blades by sharpening on a piece of sandstone I found on an outdoor stroll one day. Used it wet, sort of like a waterstone, and it worked up a super-fine slurry; it left a great, toothy bite on the edge. It's a very comforting thing to find that you can sharpen a blade on a simple rock found on the ground. Other stainless steels may not take to it quite so easily. :)


David
 
Obsessed with Edges said:
It's a very comforting thing to find that you can sharpen a blade on a simple rock found on the ground. Other stainless steels may not take to it quite so easily. :)
David
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I don't think that this can be an under estimated quality for an outdoorsman. Or anyone else for that matter. I've actually tried it both ways, and I came to prefer the slightly softer blade that can be sharpened up anywhere, on almost anything. I'll give up a bit of performance for ease of sharpening.

Carl.
 
Thanks for the replies, gentlemen.
Bucks were amongst the first knives I got into, & the tenacious burr drove me nuts.
I've been using my first Case in SS recently, & I haven't had any burr issues yet. I just touch up on a fine stone, no strop.
I assumed The Case steel produced less burr, but maybe my skills have improved over time.
 
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