s30v woes

[Cliff Stamp]

What upper temperatures are you talking about?

Secondary hardening.

Carbide precipitation does not cause transformation of austenite to martensite.

When the alloy precipitates out of the austenite it conditions it and thus martensite will form in the cooling after the temper, this doesn't happen at lower temperatures. At lower temperatures you can get other phases such as bainite depending on the TTT curves, you would not expect it in S30V though as it is air hardening. You can also get pearlite in the upper temperatures but not for air hardening steels, that would be more for spring tempering an oil/water steel.

Double or triple tempering is advisable for air-hardening, hot-work, and high speed steel tools.

Yes as these are commonly all tempered very hot as I noted, you don't get the same phase transformations with low tempers. If for example you took M2 and tempered it low, even a bunch of times, you would not transform the austensite by inducing martensite to form. You can't even minimize retained austenite with cold treatment which Landes noted which surprised me. The really high alloy steels require the conditioning of the high tempers because the austenite stabilizes extremely rapidly.

It would be a shame to have it disappear from the market, because the issues with it do not get solved and that because we fight a war over false claims that someone made somewhere about the steel.

It is simply noting that many of the reasons given to explain the performance are contradictory with the known properties of P/M's and the way the steel is currently promoted. What would be a shame is to not be very skeptical of any claims made to explain a problem because unless they are supported under critical examination the problem will persist because obviously the real issue was not determined.

From what I have read, my impression was that the differences between a piece that is allowed to cool slowly and one that is quenched/cooled with plates, is FAR greater, but my sources are only snippets off the internet.

What sources, actual materials references or just makers selling the steel? There is a wealth of materials data on the effects of air vs oil on air hardening steels, this isn't an issues specific to a couple of CPM steels. They are of course used in industry with just air hardening as that is how they were designed. You can also just ask the manufacturers directly (look at the published data) you can expect a small increase in the hardness, 1-2 points, and small effects on corrosion resistance/toughness, with the latter being also effected by the lower hardness. Landes has studied this in detail as well which is why he does water quenching after tempering so you can discuss it with him and he will be very specific about what it does. However if you don't water quench after tempering it doesn't mean the steel is ruined, again, this is a small refinement.

It is just that I have read on multiple forums by multiple people that they had problems with S30V and 3V before they employed cooling plates or other means of quickly pulling of heat.

Note the problem with S30V is generally it is too brittle, air hardening would not have this effect in general because it softens the steel. The main problems are not with rolling but chipping, though some like Sodak have noted poor edge retention due to softness which was corrected by Wilson with a rehardening. There have been some issues with 3V and deformation such as Ralph noted when he used the steel but I would be skeptical that it was a hardness issue and he never realized it and again this is an air hardening steel. Note Carpenter makes a very similar steel so you can just ask them about it. I have had a few exchanges with them about their P/M's. Knives are actually very slim cross sections and thus they cool relatively quickly due to a high area/volume ratio. Generally the main use of aggressive quenches on air hardening steels is for very large parts which such a heat capacity that they can hold onto the heat long enough to hit the pearlite section of the TTT curve.

You might also want to email Krauss who is by any defination an expert on steels and ask him about the effect of air vs oil on steels with a highly displaced pearlite nose. You could also just read his ASM reference books, which in general are invaluable references. Any decent library will have them, or will just get them on loan. He also has new editions out which I plan to buy shortly. I think I'll do a pass around if there is interest, maybe create some kind of mini-reference library.

-Cliff

 

[knarfeng]

Crucible might have shipped bad batches of S30V, but the most likely cause for these problems is poor heat treating and overheating the edge by manufacturers. .

Please pardon my meddling. I am not a metallurgist nor a knife maker. I cannot argue the carbide content nor the merits of quenching in ice. But one of my jobs is finding the sources of problems in process lines.

Judging by the threads I have read, the issue with S30V is the variability of the end results. We get reports of Sypderco Natives that are wonderful, and reports of Natives that chip. Likewise with CRK Sebenzas and BM blades. Lots of knives that are awesome, but a disturbingly high number that chip.

I do know some things about heat treating. Establishing a new heat treat regimen can require some art. Maintaining just requires good engineering. I would expect companies like Spyderco, BM, and CRK to be able to maintain a given heat treat. And if you perform the same heat treat, you are supposed to get reasonably the same results. Therefore, each product line should be the same batch to batch. But they are apparently not getting such uniformity.

If heat treat were the issue, one would expect all Natives to be good or all Natives to be bad. Likewise Sebenzas and BMs. But since we seem to be getting some knives with non-chipping blades and some with chipping blades, I have a hard time believing that poor heat treat is the issue.

One is drawn to the conclusion that there is some variability in the S30V itself rather than cost cutting or inability to maintain a heat treat schedule at top of the line knife makers.


I can't remember who uses it, but I will borrow their tag line: my 2 cents.

 

[Jerry Hossom]

Sometimes I'm stunned by the arrogance of some people thinking they know more about steel than steel companies or the people who shape, heat treat and process steel everyday and have considerable empirical knowledge of the various steels, their strengths, weaknesses and how they compare. Could that all be hype. Doubtful, but tell me something you buy that isn't hyped, including some of the opinions on this forum. How did you decide which car to buy? Are there lemons? Would it run well if the engine weren't tuned properly? Can some people drive better than others? Do some cars get harsher treatment than others? Do some people like Fords and others like Chevy's? Are most steel companies, most knife companies, AND most knifemakers ALL lying to you? I guess you have to decide if they are.

Crucible's website sucks for useful information on processing their steels, at least those used for making knives. All stainless steels benefit from a rapid quench, some of the newer ones depend on it.

Here are links to Latrobes PDF files on BG-42 and Duratech 20CV (a new powder metallurgy steel). You will note that both require oil or high pressure air cooling.

http://www.timken.com/products/spec...fo/PDF_Files/vac_arc/bearing/BG42_Bearing.pdf

http://www.timken.com/products/specialtysteel/engineering/Sheets/Stainless/DuraTech_20CV.pdf

Knifemakers and Knife Companies really don't care which steel you prefer; we don't make money on steel and make less if they require special handling. If everyone wanted D2 or A8 Modified or 5160 or whatever, we'd be happy to use it. If I thought tempering 154CM was better at 400F than it is at 950F, I'd use 400F. There is absolutely no difference in cost for me to use one or the other. I've tried both; I prefer 950F because I believe it is tougher. What's the fuss?

I've described ad nauseum some of the issues that make S30V a good steel or a bad steel and I really don't want to get into that pissing contest again. Can it be screwed up? Sure. Can it be processed so it is one of the best stainless knife steels ever created? Sure. Is it easier to machine than D2; you'd have to be insane to say that without having machined it, and after hardening it is even worse, requiring twice as long as any other steel I use to achieve the same finish. I hate the stuff.

Another point, S30V does not vary from lot to lot. There are occassional (rare) tiny voids, but after over a half ton of the stuff, I've only seen that in one knife I made and it was just one small void. Performance does not vary. If there were ANY lot-related variables in the steel, Crucible representatives would not survive the next knife show they attended. Knifemakers are completely unforgiving about that kind of thing.

'Nough said...

 

[Cobalt]

Another point, S30V does not vary from lot to lot. There are occassional (rare) tiny voids, but after over a half ton of the stuff, I've only seen that in one knife I made and it was just one small void. Performance does not vary. If there were ANY lot-related variables in the steel, Crucible representatives would not survive the next knife show they attended. Knifemakers are completely unforgiving about that kind of thing.

'Nough said...

thanks, this was really good to know. Shows how high the quality of the steel is. So if you get the HT right, then you're good to go. Unfortunately it sounds like there are still many companies who are not getting the HT down right.


edited to add: Why do we have another long thread on this, when there was one going on, on the review forum. Can't people just do the search function first?

 

[Dog of War]

Sometimes I'm stunned by the arrogance of some people thinking they know more about steel than steel companies or the people who shape, heat treat and process steel everyday and have considerable empirical knowledge of the various steels, their strengths, weaknesses and how they compare.

There's certainly a valid point to what you say, Jerry. But it's really not much different than someone saying:

"I'm stunned by the arrogance of people who think they know more about economics, foreign and military policy, and important global issues than the elected officials of this country, whose job it is to be informed about these things and whose lives are dedicated to dealing with these matters."

As it turns out those arrogant people who think they know more than the supposed experts are the voters who ultimately decide the fate of politicians and what our economic, military, etc. policies will be. Your statement suggests that you think the knife buying public and even knife enthusiasts are mostly ignorant - too ignorant to even form valid opinions. Maybe you think the citizens of the US are too ignorant to vote? IMO those are pretty arrogant opinions themselves.

Or are you going to tell us that your comments are actually aimed at just one or a few posters here who you seem to have some running dispute with?

 

[SteelDriver]

No, I am stating that those who used S30V and have had problems have used very hard to grind steels like D2 and thus they would be well familiar with how to grind such steels. I also noted that you have to exceed the tempering temperature significantly in order to soften a steel and that this will not have a dramatic effect if the steel has significant temper resistance, you are essentially just giving it a very short temper at that elevated temperature and you noted that S30V has a long temper time which again means it is temper resistant. Examine the temper responce of S30V to see what kind of temperatures would be required to produce a significant softening, the data is in the spec sheet.

So, all the users of S30V have also worked with D2?

By your reasoning 154CM, S30V, S90V, BG42, O1, A2, D2, and plenty of other tool steels are impervious to edge overheating after HT. All of them temper at 400°F or above, with a recommended 2 hour minimum temper. But some let you get away with 1 hour per inch of thickness. Now why would the tempering time depend on thickness?

No, your point was illogical. You cited an example of a un realistic systematic defect, do you really think companies are deciding not to temper S30V but are for VG-10 - that is obviously absurd.

Like I said, you missed my point. The difficulty of heat treatment is irrelevant when you're getting it wrong in the first place. Hence my example of O1, though commonly regarded as easy to heat treat, can still be screwed up. You can't blame that mistake on the steel. A manufacturer could be spot-on with its HT for all other steels, but if it believes that S30V can be single tempered or quenched slowly in air then it will get poor results with S30V. Your reasoning, that consistent results with other steels means consistent results for S30V, is flawed.

No it doesn't. This assumes that the same percentages I noted in the above hold for customs and production blades and this is obviously not the case. You would expect a massive increase in reported problems for production blades even if both populations had exactly the same defect rate.

Again, you missed my point. I said if the problem were inherent to S30V as it arrives from Crucible, we'd be seeing the same problems in custom knives regardless of maker. So again I ask, in your opinion what's causing these problems?

 

[EDCeeker]

Sometimes I'm stunned by the arrogance of some people thinking they know more about steel than

Sometimes I'm stunned by the arrogance of so-called experts that seem to be of the opinion that because they are "experts," they should never be questioned or doubted. Most-often seen in professionals such as doctors, lawyers, politicians, but by no means limited to those professions.

'Nough said...

Just because you say it, doesn't make it so. In fact: It's been my experience on the 'net, lo these many years, that assertions such as this, "end of story," etc. are generally nothing more than attempts to stifle further discussion. It's also been my experience that people who truly do know what they're about, and are arguing from firm ground, never say such things. They don't have to.

Now, back to the subject-at-hand...

A knife-maker you may be, Jerry. And as no more than a knife knoobie, myself, I must bow to your (assumed) greater knowledge of steels and steel-working. However I cannot help but observe that, your arguments notwithstanding, there does seem to be something amiss with S30V, whether it be with the supplier or the one who turns it into a knife. Something from which the other "high-end/-tech" steels don't seem to suffer.

In the end, as the buyer, I'll take a pass on S30V blades for the nonce.

 

[mete]

EDCeeker, so you're going to reject a fine steel because someone has a problem ? My S30V is a Sebenza and I'm very happy with it , no problems. As a metallurgist who has worked for a steel company and other companies I am well aware of the whole process. A good steel is only as good as the heat treatment .You ought to read through the 'Makers' section and see how many there are who think they can HT a complex stainless steel just like they do with 5160, they are clueless. In manufacturing many take shortcuts for lack of knowledge or to cut costs. ..Don't condemn a fine steel because a few have had problems without knowing exactly where the problems came from.

 

[db]

No, your point was illogical. You cited an example of a un realistic systematic defect, do you really think companies are deciding not to temper S30V but are for VG-10 - that is obviously absurd.

Are companies that use both of these steels heat treating them in the same place?

all P/M's are actually easier to heat treat and more forgiving because of the finer and more consistent structure.

WOW! Did Cliff really write that?

 

[Cobalt]

EDCeeker, so you're going to reject a fine steel because someone has a problem ? My S30V is a Sebenza and I'm very happy with it , no problems. As a metallurgist who has worked for a steel company and other companies I am well aware of the whole process. A good steel is only as good as the heat treatment .You ought to read through the 'Makers' section and see how many there are who think they can HT a complex stainless steel just like they do with 5160, they are clueless. In manufacturing many take shortcuts for lack of knowledge or to cut costs. ..Don't condemn a fine steel because a few have had problems without knowing exactly where the problems came from.

I agree with what you have said, but in the end if you do not know if the maker knows how to HT his product then what? You switch to something else. I won't take a chance that something will fail, when I know there are other steels out there that have not nearly the issues.

who's going to post a list of makers, custom or production that have no clue what they are doing in the HT department? Will you? I doubt it. That would be akin to shutting down their business quite likely.

 

[hardheart]

Is S30V cheaper, easier to machine, or providing superior results on average compared to other stainless? What's the reason to use it, and is it worth the risk of bad batches, difficult HT, more demanding sharpening, or any other suspected causes of reported problems?

If I thought tempering 154CM was better at 400F than it is at 950F, I'd use 400F. There is absolutely no difference in cost for me to use one or the other.

I'd say you would notice a bit of a difference on your utility bill. Considering how many hundreds of knives the manufacturers make, this is a definite cost consideration for them. Now, is it worth it to use a steel that requires 950 over 400, or two hours instead of one, or any other increase in cost & time for targeted performance? It is if the customer wants it and will pay for it. But, why does the customer want it? Does the customer know enough about the alternatives to choose intelligently? Does the customer choose rationally?

It's just steel, but it can get complicated.

 

[Cobalt]

Is S30V cheaper, easier to machine, or providing superior results on average compared to other stainless? What's the reason to use it, and is it worth the risk of bad batches, difficult HT, more demanding sharpening, or any other suspected causes of reported problems?
.

and this is presumming bad HT and/or material batches. There is the thought of possibly it being bad due to it's manufacturing method, particle metallurgy. No definite grain direction like particle board versus regular wood planks that have grain direction. Unlike steels that are rolled from large castings of 8 inches in thickness or more which gives a direction of grain strength.

I have asked this question in the past and gotten no direct answer: If powder metal castings are not significantly rolled down to make useable stock, then the grain boundaries have not been forged and what you are machining is a casting. Castings are all but worthless in the metal industry. Race car engine parts are forged for a reason, extreme mechanical strength at high RPM's.

If the powder metal castings are small and require little to no reduction by roll mill, then the implied mechanical advantages on paper are probably not there in reality. But I don't know this to be true since I have never seen a discussion on how large the castings are. I know that they most likely are not large because if they were, then cooling of the inner core of powder would be difficult causing even worse grain adhesion issues with not fully welded grain boundaries.

 

[bladeprince]

This isn't a technical post as I am not knowledgeable with the intricacies of metallurgy. This could be an incorrect observation but I don't remember anyone ever post a chipping issue with the Ritter S30V Grip. I have one myself, use it and sharpen it to 30% with a 40% back bevel and have never had any chipping problems. But I haven't had any with Spyderco knives so far so that may not mean much. The chipping issues I've had are with a BM Ruckus and a Lone Wolf T2 double action (which I returned for a different reason). I’m just wondering if my observation is correct. Is the S30V on the Ritter Grip less prone to chipping?

Regards

 

[Jerry Hossom]

Sometimes I'm stunned by the arrogance of so-called experts that seem to be of the opinion that because they are "experts," they should never be questioned or doubted. Most-often seen in professionals such as doctors, lawyers, politicians, but by no means limited to those professions.

Just because you say it, doesn't make it so. In fact: It's been my experience on the 'net, lo these many years, that assertions such as this, "end of story," etc. are generally nothing more than attempts to stifle further discussion. It's also been my experience that people who truly do know what they're about, and are arguing from firm ground, never say such things. They don't have to.

Now, back to the subject-at-hand...

A knife-maker you may be, Jerry. And as no more than a knife knoobie, myself, I must bow to your (assumed) greater knowledge of steels and steel-working. However I cannot help but observe that, your arguments notwithstanding, there does seem to be something amiss with S30V, whether it be with the supplier or the one who turns it into a knife. Something from which the other "high-end/-tech" steels don't seem to suffer.

In the end, as the buyer, I'll take a pass on S30V blades for the nonce.

Interesting post.

Where did I say I shouldn't be questioned? Better yet, where did I say I was an "expert"? I claim only to be a knifemaker who has used the steel and is aware of some of its strengths and weaknesses of which there are both, as I have mentioned in other threads on this and other forums.

I really didn't say "end of story". I said " 'nough said" meaning I had nothing further to add; clearly there is more to discuss. Perhaps what I said or the way I said it was flippant, but it was not meant to imply that the subject wasn't worthy of more discussion. If I misled you, I apologize.

I agree there is something amiss with S30V, no small part of which is a lot of misinformation. There are also some legitimate concerns by people who have used it and found that it chipped or lost its edge quickly. Those, in my experience, are symptoms of poorly processed or finished steel. Other high tech steels DO indeed suffer from many of these problems, just not as severely.

What many may not know is that a lot of custom makers changed there heat treating protocol as a result of S30V. Most learned it couldn't be successfully hardened unless quenched quickly. One of the problems for little guys who don't have environmentally controlled ovens is that they have to wrap their blades in stainless foil so the steel doesn't decarburize at hardening temperature. Since the blade is in an envelope, there is a layer of insullation around the steel that slows cooling dramatically. Where 154CM would harden properly; S30V (CPM-3V and as you can see from the Latrobe literature that applies to BG-42 and 20CV as well) would not. So S30V is not alone with its problems; just more noticeable maybe. Most knifemakers solved that problem with quench plates, usually large slabs of thick aluminum, that are used to sandwich the hot wrapped steel and draw off the heat quickly. This need for a rapid quench was one of the reasons a number of knife companies didn't jump on S30V as soon as it came out. Using conventional ovens, it's very difficult to heat treat large batches of S30V blades. As you might imagine large batches of blades means large thermal mass and a more difficult cooling process. It's my understanding that most now use salt bath hardening. So there is a variable that can account for some knives in S30V working well and some not well at all.

That's the reason I don't do my own heat treating. I don't think I can do it as well as a professional heat treater.

The decision not to use the steel is not really an issue. Everyone gets to choose what they like and what they don't. That really was one of the points I was trying to make. If NOBODY chose S30V, my life would be much simpler and I could increase my per knife productivity by about 30%. Hype? More than a third of my knives are in 154CM (now CPM-154), because most people can't really tell the difference between that and S30V. No reason for them to pay more, and those who really do need the extra performance should.

Going back to those experts you list, I agree. I worked in the medical field for almost 30 years. Some of them are a little short on humility. I'm not an expert. I do like to think of myself as a knowledgeable knifemaker, nothing more.

 

[SpearZ]

I haven't got the thread to show you but I have read somewhere that Curicble steel put out an alert that a bad batch of S30V had been made after getting many complaints from knifemakers etc.

 

[Jerry Hossom]

I believe that was true, but the problem related to excessive voids, not the chemistry. It's REALLY annoying to put a couple hours into finishing a blade, only to find there is a small hole on one side of the blade. Even a very tiny hole is a trashed blade and a very irritable knifemaker.

 

[Kohai999]

The decision not to use the steel is not really an issue. Everyone gets to choose what they like and what they don't. That really was one of the points I was trying to make. If NOBODY chose S30V, my life would be much simpler and I could increase my per knife productivity by about 30%. Hype? More than a third of my knives are in 154CM (now CPM-154), because most people can't really tell the difference between that and S30V. No reason for them to pay more, and those who really do need the extra performance should.

Going back to those experts you list, I agree. I worked in the medical field for almost 30 years. Some of them are a little short on humility. I'm not an expert. I do like to think of myself as a knowledgeable knifemaker, nothing more.

Jerry,

We sometimes disagree about stuff, but your posts in this thread have been right on!

Cliff and his minions of (mostly) total newbs that maybe just got driving learner's permits want to, ahem, split hairs about things that they(mostly) have no understanding of to begin with, and would greatly benefit from knowing when to STFU, but they don't. Having a PHD in Molecular Whatever, does not necessarily qualify you to tie your own shoelaces.

Heat treating is a science. What makes some qualified to mess with steel company provided schedules(Wilson), and others not(other makers) is sort of a mystery to me. Paul Bos does a very fine heat treat, and so do other professionals, provided that they have the tools to follow the schedules as set from the steel companies. In other words, that they can get the steel hot enough, long enough, and then cool it down fast enough.

If you want to use S30, great, D2 great, 154CM, great. If you don't want to use a steel, don't. Better yet, continue to explain to people why you don't use it. Educated education is the best kind.

Best Regards,

STeven Garsson

 

[Cliff Stamp]

So, all the users of S30V have also worked with D2?

The experience with hard to grind steels is common yes because wear resistance is pretty much the dominant promoted aspect of most knives now. Since the problem exends to makers/manufactures who have used D2 and even steels like S60V/S90V it can not be argued that lack of experience with hard to grind steels was causing the problem and again this was again one of the improvements of S30V over S60/90V, it is easier to grind, not harder.

By your reasoning 154CM, S30V, S90V, BG42, O1, A2, D2, and plenty of other tool steels are impervious to edge overheating after HT.

No they are resistant not invunerable, some more so than others. BG-42 and D2 both have commonly very high tempers. BG-42 is in fact a HSS and will resist softening even when ran very hot. Yes there is a massive difference in how easy you can draw the hardness on M2 vs 1095 or 154CM vs O1. Just look at the temper responce curves. Again, actual published materials data.

Like I said, you missed my point.

You claim that heat treating issues are a problem but ignore that other steels are fine so your example isn't supportative of your arguement because you cite an issue of gross incompetance which would effect all steels.

A manufacturer could be spot-on with its HT for all other steels, but if it believes that S30V can be single tempered or quenched slowly in air then it will get poor results with S30V.

You have actual materials data to support this? Again I am not saying multiple tempers are a bad thing, nor that you should not consider aggressive quenchs on air hardening steels, but the claims made in the above are highly exaggerated with no materials support.

Again, don't take my word for it, read the references I have provided and ask an unbiased independent perspective such as from Landes or Johnston who will provide you with published reference materials to support their arguement. I did.

Why are you taking anything on faith from a salesmen. Ask for direct materials data to support the claims. Ask for facts on the effects of the heat treatment. What is happening in the air/single temper issues which is supposed to cause such a drastic embrittment.

Now take that proposal and discuss it on SwordForums with the number of independent metallurgists there and see if it holds under critical examination. Bring it to rec.knives and see if it holds up to Johnson's ASM based arguement.

So again I ask, in your opinion what's causing these problems?

Until you have actual actual materials data provided it is just conjecture. Ask for information on the grain size, carbide segregation, untempered matensite, retained austenite, voids/impurities, grain boundry carbide precipitation, actual type of crack failure method (through grains, along boundries) etc. . These are the questions that need to be answered to actually solve the problem.

How did you decide which car to buy?

In general I discuss such issues with people who have used the items not the people who make them or are trying to sell them. I also based the decisions on experience I have with items of similar properties or deduce them from known properties and published data. What do you do, go ask a salesmen and blindly buy what they tell you?

Knifemakers and Knife Companies really don't care which steel you prefer

P.T. Barnum would be proud.

Obviously it is preferred if the customers want the steel being made and in particular if it can be claimed there is something special about it that makes it unique. Hence the constant promotion of "special" heat treatment and the use of labels like Carbon V vs 50100-B. There is also usually a complete lack of actual data to support such uniqueness as actually being superior.

And no it isn't all hype. There are lots of makers who are very frank and not overly promotional. You would never know Wilson was a knife maker when talking to him unless you asked because there is no sales pitch. Cashen and Johnston are the same, all of those three are very active against hype and over promotion of steels. Kirk and Martin are also solid sources of information as are many others.

There are also a bunch of very informed individuals who have no significant monetary connection to the industry like Landes who can be asked for unbiased opinions and who use published materials data to support their statements which is also based on significant use of steels in knives and extensive personal experience heat treating steels specifically for knives.

What's the reason to use it ...

It has a high wear resistance and is cheaper and easier to grind/heat treat than S90V. It is thus basically inbetween ATS-34 and S90V. If you have not used a decent one them drop me an email and you can try out the South Fork from Wilson. The high wear resistance offers good cutting lifetimes on abrasives materials like cardboard and the hardness is comparable with most current cutlery (60 HRC) so expect similar resistance to rolling/deformation. The knife is also really optomized for cutting so sets a nice benchmark for high flat grinds. I prefer his enclosed handles but this design cuts down on the cost so is an option for those with not unlimited funds. It isn't a tactical design, so no significant prying/impacts and the edge is very thin/acute so it won't handle metals/bone well. I don't care if it does get damaged accidently though or if you are curious as to how bad it will get damaged if you push it a little hard like cut up a few staples or open a can of tuna. Just don't try to chisel cut a nail or similar as you will blow the primary grind easily. If you want to check that out then I can send you a production S30V knife in a similar profile and you can mangle that to any desire you want to see the limits of the steel.

No definite grain direction ...

P/M's have a significant grain due to rolling this is why they impact test different in the longitudinal/transverse directions.

If powder metal castings are not significantly rolled down to make useable stock, then the grain boundaries have not been forged and what you are machining is a casting. Castings are all but worthless in the metal industry.

The reason that you have to extensively roll cast ingot steels, especially the high alloy ones is to break up the dendretic carbides and try to make the composition more uniform. It would be expected that P/M's would thus require less rolling because they inhernetly have a much better alloy distribution and far less segregation. Compare the micrographs of ATS-34 (ingot) vs RWL34 (P/M) I posted that Landes took for example. Note that P/M's are essentially just a bunch of very small ingots that are forged welded by compression. They are also then rolled.

In general, for similar alloy composition, P/M are tougher than ingot steels, there is a wealth of published data on this all due mainly to the lower segregation and more uniform composition. P/M's are in general a good thing and the main reason they are not used more is just cost, it is cheaper to make ingot steels. You have to be aware though that alloy composition has to be considered. RWL34 for example has way larger and more segregated carbides than 13C26 just like P/M-M4 has a lower edge stability than W1. This is why the of similar composition has to be noted when such generalities are given.

This could be an incorrect observation but I don't remember anyone ever post a chipping issue with the Ritter S30V Grip.

I have used one which was defective which was itself a replacement for a defective knife. Problems have also been seen on other Benchmades.

-Cliff

 

[EDCeeker]

It's REALLY annoying to put a couple hours into finishing a blade, only to find there is a small hole on one side of the blade. Even a very tiny hole is a trashed blade and a very irritable knifemaker.

I imagine that in writing "very irritable," you're employing "British understatement" in a very big way . Yeah, I can definitely see that. I have no idea, except in the most vague and general terms, of how one goes about turning a hunk of raw steel into a finished blade, but I imagine it's a lot of work.

 

[EDCeeker]

...I don't remember anyone ever post a chipping issue with the Ritter S30V Grip.

I do. I was going to buy a Mini-RSK and was researching it, here on BF and elsewhere, when I first ran across talk of S30V chipping issues. S30V chipping issues was the primary reason I dropped my plans for a Mini-RSK and ended-up with a Spyderco Delica 4.