S30v

This was a long and interesting thread to say the least, although as a newbie and a steel/metallurgical moron I did learned plenty, both from "ELU's" and "those in the know".

What did I learn? I'd like to take 2 quotes from Mr. Martin on post #110 -

1. As with ALL steels, it's the HT which he says: "if the HT is done correctly".

2. "from an engineering and materials perspective, this stuff is awesome."

Personally, I'd like to compare it with another yet ubiquitous product: the cellular phone (nowadays it's more like "who hasn't got one?" rather than the other way around). Arguably, the Finnish "Nokia" brand is the most well known and forerunner among it's kind and every year it comes out with another top-of-line, state-of-the-art, all-in-one feature-laden model phone that it markets to a willing consumer. Then a little later when some of the "hype" subsides, we also hear reports of how this latest model suddenly conks out in the middle of call, or the built-in video's resolution adjustment isn't what it's cracked up to be or just how cumbersome it is (because of all the features crammed in it!), etc. Was the product/model SUPPOSED to be a good one? Definitely. When the reports or second-hand info started coming in about it's flaws or shortcomings, does this mean the product/model was awful? Not really. Did it have a couple of "bugs" in it that needed to be straightened out and improved upon for later models? I suppose so.

This is why the informed consumers adopt a "wait and see" upon the introduction of a new product. Rarely do we have things "perfect" on the first go.

BTW, my experience stems from having a 2-month old Spyderco SWICK. I bought it initially for SD purposes but the because of it's handly design, I thought it'd be a good general purpose cutter. All this time the only "hard" material I remember subjecting it was on small fallen branches on the farm (softwood, some even green). I'd also used it in cutting CD wrappings, an old sofa cushion with leatherette and some folded newspaper. In short, I've been "spoiling" it when you compare to what I've subjected my Endura to! The micro-sized chipping is evident even to the naked eye. This is what has led me to my conclusions above.
 
Colbalt, I have done a lot of work with S60V and S90V, (440v and 420V). Just as a clarification it would be very difficult to get either to a final hardness of 63 unless one ingnored the temper cycle. The best hardness for 60V is 58 on the high end and 60/61 for 90V. They do tend to be brittle if you go any higher than that. S90V I think makes a great hunting blade, a slicer not a chopper. Great edge holding, reasonable toughness and good corrosion resistance. I have probably a couple of hundred S90 V blades, both hunters and fillet knives out there in use in the field and I have never had a complaint about chipping or breaking with that kind of use. I also use them myself with the same result. Only one case of chipped blade and that was admitted that the user was prying a joint apart and got a dime sized chip as a resut. Phil
 
Phil Wilson said:
Colbalt, I have done a lot of work with S60V and S90V, (440v and 420V). Just as a clarification it would be very difficult to get either to a final hardness of 63 unless one ingnored the temper cycle. The best hardness for 60V is 58 on the high end and 60/61 for 90V. They do tend to be brittle if you go any higher than that. S90V I think makes a great hunting blade, a slicer not a chopper. Great edge holding, reasonable toughness and good corrosion resistance. I have probably a couple of hundred S90 V blades, both hunters and fillet knives out there in use in the field and I have never had a complaint about chipping or breaking with that kind of use. I also use them myself with the same result. Only one case of chipped blade and that was admitted that the user was prying a joint apart and got a dime sized chip as a resut. Phil


Maybe the fact that all these steels have a very high carbon contact, makes makers want to push the Rc to the point where the edges crumble and you are right. I have to admit my older 440V blades could hold an edge forever but were a bear to sharpen. Thanks for the response Phil
 
Cobalt, discussion of S60V is off the subject but what I was trying to get at was that S60V has a low obtainable hardness. Even with a high soak temp. of 2050 and an oil quench the as quenched hardness is 61/62. At a temper of 400 the finished hardness would be about 58 or less. I have seen other references to this steel being hardned to 63 or higher and that is just not possible. Most times it is used around 56. This is where it has the best properties for a knife blade. higher than that and it is starting to get pretty brittle. S90V has a much higher obtainable hardness and it is possible to use it up as high as 61/62 as a slicing type blade with sucess. PHIL
 
Phil Wilson said:
Cobalt, discussion of S60V is off the subject but what I was trying to get at was that S60V has a low obtainable hardness. Even with a high soak temp. of 2050 and an oil quench the as quenched hardness is 61/62. At a temper of 400 the finished hardness would be about 58 or less. I have seen other references to this steel being hardned to 63 or higher and that is just not possible. Most times it is used around 56. This is where it has the best properties for a knife blade. higher than that and it is starting to get pretty brittle. S90V has a much higher obtainable hardness and it is possible to use it up as high as 61/62 as a slicing type blade with sucess. PHIL


Makes a lot of sense, but can't the same be said for ATS34 and 440C. They have always been good steels and only recently found wanting. Could it be that the Rc of these steels was beng pushed to far. It's not untypical for ATS34 to be Rc'd at 61-62
 
Cobalt, all steels have that point where hardness peaks and impact toughness starts to diminish. One of the reasons is that to attain the high hardness, the lowest tempering temperatures are used. This puts the materials at a high risk of not getting fully tempered and stress relieved. With grades that have secondary hardening peaks, like ATS 34 and 154CM you can get 61-62 via low tempering or secondary hardening with higher tempers. The lower gives best corrosion resistance and the higher one gives lower corrosion resistance but better ductility. Which is the best is strictly up to application and personal preference. No real right answer there. 440C at 62 is definately being pushed too far. In almost all commercial applications 58-60 is the specified range. I'm talking food applications, fuel injectors, etc. The reason you see 440C pushed to the limit is that in thin blade sections you can get there, but depending on the process it will be hit an miss on the heat treatment. Just because you can doesn't mean you should.
 
Satrang, Colbalt, Again a little of subject but I don't think that it is common to see ATS34/154CM at RC 62 in a knife blade. As I mentioned before this steel is difficult to get that high in real practice. Only with a high soak temp, oil quench, subzero and using the high temper to take advantage of the "bump" can you get it there. I can usally get 61 on this one and that seems to be the high end for reasonable toughness. At least in a knife blade application. Hardness testing is also all ove the map and you can only be sure of what some are saying about what the hardness is when the equipment is constantly calibrated with the real Rockwell std. test block. In other words don't always belive what you hear in this regard. PHIL
 
I would also like to mention that the new one CPM 154 is much easier to heat treat. RC 62 on that one is real. I have a fillet knife of my own in use now at that hardness and it is great. Excellent edge holding and plenty of toughness for this use. It grinds and finishes nice also. I am pretty sure Satrang was the guy who came up with this one when he was working at that "other" place. I pat him on the back for this steel. I think as time goes on and others discover it it will fully replace 154CM. PHIL
 
Phil, I'm with you on the attainable hardness of the ATS/154 topic. You can get there but for all practical purposes 62 is the max and not always the best target for the materials. I think max hardness is a poor way to look at materials. Balance is key.
 
This thread has been an interesting read (I lurk around here at times, but seldom post).

I bought a Spyderco Native out of S30V a while back after reading threads here basically praising the knife and the steel. After reading the current thread ... I'd still buy a knife made with this steel. I know nothing about metalurgy, knife manufacturing techniques, etc. I trust Spyderco made a good decision using this steel. It may not be the perfect steel, but it does the job I need and does that well. It is the best performing steel I have ever personally owned (note: I am not a high-dollar collector, just someone who likes knives for their utility and appreciates decent quality at a fair price.) If I ever have any Native/S30V problems I think might be attributed to a manufacturing defect, I'll call Spyderco and ask them about it. I'm thinking about driving down there today and buying a Delica 4 or Dragonfly (these look to fit my definition of decent quality at a fair price). I guess if I was to pay more for my knives than my typical $75 +/- $25 I'd be more worried about finding the perfect steel (as opposed to "damn good").

p.s. - Does anyone know if the Spyderco outlet store carries a full line of their current knives? How are their prices there (full retail or somewhat discounted)? There was a 20% off coupon in the Denver paper the other day and that's why I'm considering a visit today.
 
Phil Wilson said:
Satrang, Colbalt, Again a little of subject but I don't think that it is common to see ATS34/154CM at RC 62 in a knife blade. As I mentioned before this steel is difficult to get that high in real practice.

Hardness testing is also all ove the map and you can only be sure of what some are saying about what the hardness is when the equipment is constantly calibrated with the real Rockwell std. test block. In other words don't always belive what you hear in this regard. PHIL

Makes sense and I am sure that the real Rc is no where near the advetised Rc. I am pretty sure that I have seen 62 listed many times for those steels.

Another big problem is the fact that too many knife company's/makers/and users look at Charpy values as the be all end all in their knife usage. The truth is that while the charpy value can point you in the right direction, it is in no way indicative of how a steel will react when it is HT's by different people, Ground geometrically different and impacted on it's edge and not a square shouldered sample. Too many factors to really take Charpy seriously. Yet, we all ook at those values.

What do you think of ZDP189 as compared to CPM. Look at the Rc's they are getting out of that steel.
 
I know I'm a bit late on this, but I was on holiday and had no decent internet access.

I'm one of those who had some problems with S30V and S60V. I had a Spyderco Native in S60V chip quite badly when I did some work in the garden, trimming back a couple of bushes. Nothing outrageous, certainly no abuse. After a couple of sharpenings these problems disappeared completely. That was my second Native in S60V, my first one never had any such problems, and I used that knife really hard for a couple of years, doing a lot of things you normally wouldn't do with a knife. I reckon the Native that chipped got too hot at the edge when it was sharpened at the factory. The sharpenings got rid of the damaged steel.

I also had a Manix that chipped easily. Once again, there was no hard use involved, and certainly no abuse. I don't have that knife anymore, so I don't know whether the chipping problem disappeared after sharpening. All my other knives in S30V are OK. My most used knife at the moment is the UK Penknife, and it does pretty well, even though I tend to use it quite hard.

My own feeling is that S30V is a good stainless steel. Good wear resistance, no big problems with corrosion. What I *don't* like about it is that it doesn't readily take very acute edge angles in my experience. I find angles below 10 degrees aren't very useful as the edge just doesn't hold up to everyday use. And S30V doesn't readily get as sharp as some other steels, at least not in my experience.

So, all in all I wouldn't call it the *best* stainless steel out there, not even for smallish folders, but it's a good compromise. But so are several other steels, like VG-10, one of my personal favourites, or 12C27, a very nice steel when run pretty hard. They've all got their strengths and weaknesses.

Hans
 
Cobalt said:
What do you think of ZDP189 as compared to CPM. Look at the Rc's they are getting out of that steel.
I think earlier in this thread Phil Wilson gave his thoughts on a piece of ZDP189 he used comparing it to S90V.
 
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