CPM S30V vs BG-42 steel

Mike Kerins

Mike Kerins

Joined
Nov 14, 2004
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I may be opening up a hornets nest but here goes! I'm looking to buy an EDC pocket knife, preferrably with a nice titanium clip. My dillema is what type of steel to settle on. I've seen conflicting reports giving S30V the edge and others giving BG-42 the edge. The issue seems to be the degree of hardness S30V is developed for. I've read that although it has the capacity to be finished with an HRC rating of 61-62, it is actually finished at HRC 57-58, where BG-42 is finished at HRC 59-60. The speculation has been that S30V is finished at a lower HRC for ease of production. Someone please enlighten me as to the actual truth so I can make an informed decision. I want a steel that will retain an edge with every day usage, and with maximum sharpness. Ease of sharpening is not really an issue with me. If it really keeps an edge well, sharpening would be an infrequent task.
 
I'm really glad you came here to ask that question! It's an honest one. I'm glad you're doing your homework. But I think it's the wrong question.

I think brand is more important than your steel choice. In otherwords, a well made 440A blade will out perform a poorly made S30V.

Beware of blanket statements like: "The speculation has been that S30V is finished at a lower HRC for ease of production." Who the heck knows what decisions a manufacturer makes or why. Heck, they might charge enough extra for S30V that even if it takes twice as much work to finish they make more money than BG-42. (I don't know, that's just a contrary example for demonstration purposes.) There's no way every manufacturer will make the same decisions like that.

So, now the question has to be: Manufacturer A offers 2 steels, which one do you think they put more work in?

Then it has to be what's your criteria. Doesn't sound like appearance is an issue for you. Toughness isn't a big deal in folders. So, all that considered .... heck if I know? I was just trying to be a pal and clarify your question.

Steve
 
Roger is a S30 pro, too. You probably use S30 for 80% of your knives, don't you, Roger? Roger does a grand job of HT. I would go the S30, following and expert's (Roger's) example. Also, it comes down to what was mentioned before by Steve, how the steel been treated.
 
I've heard (no direct experience) that BG-42 is a beautiful steel and can take a great finish - in the right hands.

Steve
 
I really appreicate all the information. I normally prefer function over form, but I also appreciate a true "work of art" when I see it. I'm looking for a very capable EDC that I can carry without having to put it on my belt. I really appreciate the issue of brand over material. I wish there was more information related to just how the diffreent materials were handled during the manufacture process. Absent that level of detailed information, I guess maker reputation would have to do as a proxy. So far I'm hearing that S30 has the edge (pardon the pun) provided it is used by the right maker. :)
 
Hardness in itself is not the only measure of a blade and you shouldn't pick one based on 1 or 2 points difference. The S30V is a CPM steel ,made differently and offers advantages [small evenly disributed carbides] over BG-42 which is a bearing steel of very high quality.While I have a well made S30V I don't have a BG-42 to give a direct comparison .While S30V may be better you wouldn't be disappointed with either one.
 
I have only heat treated one BG-42 blade. My experience with it is practically nil. For that blade I went strictly by the data sheet. The tempering curve was extremely tight, like about 15 degrees F before beginning to fall off very steeply. My opinion is that BG-42 requires much more attention to detail in the tempering phase of the heat treating process. Because of that tight curve I know my equipment is limited to pretty small BG-42 blades.

RL
 
BG-42 takes a nice finish, so does S30V, it's just a nightmare to get it there. I'm not sure a mere human could tell the difference in edge holding ability between S30V and BG-42. I know I couldn't but if I had a choice, I'd take a little less mirror finish and go with the S30V.
 
I don't think that you should worry about the modest difference between the two alloys. I would be happy with either one. What I would not want to do is insist that a knife maker who usually uses S30V should make me a knife from BG42 or vice versa. I would look for a design that matched my needs then I would decide if the maker or manufacturer has experience and a reputation for producing good blades with the alloy that they are promoting. If they send out the blades to a heat treating specialist I would want to ask the same question about the HT guy.

I have liked blades heat treated by Paul Bos. I think he could do either one.
 
I think, based on my last post, Paul Boss might be a best over all choice for HT'ing a BG-42 blade. CPM S30V is not a difficult high alloy to properly heat treat - as high alloys go - and there is one or two or more makers here I would well trust for that. My hat is NOT in the ring BTW. My plate is plenty full enough for now but one maker that immediately comes to mind is Steve Sando. My freind Steve might prefer me not recommending him but what I might suggest anyhow is that if you are so particular you might want to not go with a production knife.

RL
 
A few years ago I did a huge post on this subject that led to a nasty flame war by steel snobs.

But here is the flat out truth of the matter.

For the everyday knife user, it is impossible to tell the differance between most of the good stainless steels. So long as you buy from a good manufacturer, the steel is a minor concern. Be it ATS-34, 154CM, S30V, S60V, BG-42 or several other good stainlesses; they will all perform about the same. The only differance is rust and that is IF you perform no maintainance on your blades ever. Just a casual wipe on your pants leg is enough to balance out that problem.

More important is handle comfort, blade shape, lock design ect. The stuff that is going to effect the way you use the knife.

Don't believe these guys who say they can tell the differance in performance after opening letters for a week with a knife :rolleyes:. These are the same blowhards that claim they can see 0.0001" imperfections or mirco-crystal structure with their bare eyes.
 
R.W. is giving you the straight scoop.The main concerns on a folder are 1) The manufacturer 2) the style 3)Workmanship . Either S30V or BG-42 will produce a top notch blade.The difference in hardness would be inconsequential in a folder.It is a balance of toughness and hardness that better minds than ours have worked out for us.Don't loose sleep over 1 or 2 points of HRC ,in a folder the part that fits your hand is the part to be concerned with.It will wear out (or wear you out) long before the blade does. - SA
 
R.W.Clark said:
A few years ago I did a huge post on this subject that led to a nasty flame war by steel snobs.
Click to expand...

Dude! I can see why ;)

I agree, well maybe not quite as emphatically, but definately in principle.

Real knives are kitchen knives. In that environment I think there's a little more difference in steel that your post implies.

I have to admit I'm a techno-stats nut. So I'll compare the hardness of vanadium carbides vs. chromium carbides and all. That's lots of fun to do. Lots of people like comparing statistics. That's probably where they are coming from.

But your post makes a good real world point.

Steve

PS Roger, thanks for the support. I'm not doing folders ...... yet :)
 
Ok, so then what would be the difference between the two when it comes to tip strength and edge strength on say a flat ground blade if, for instance, the knife was used to do something like open an oyster?
 
I used to work at Emmett Watson's Oyster Bar. My personal daily record was 40 dozen. I couldn't schuck any more after that.

The ONLY knife that should be used to open an oyster is an oyster knife. That is if you are opening the oyster properly. If you are right handed, hold the oyster in your left towel wrapped hand. Wedge the knife in at the joint(where the two shell halves meet at the smallest part). Pop the shell apart with a twisting motion, and cut the adductor muscle in one motion. Discard the other side of the shell, and cut the other side of the adductor muscle and flip the oyster, presenting the neatest appearance. (Sorry if this is highjacking, but I am making a point)

The best custom oyster knives I have seen are from 440C. Which is a GREAT steel, depending on heat treat. It was just the first stainless primarily used in knives, and has lost some cachet due to time.

Best Regards,

STeven Garsson
 
Tazz, all things being equal, I don't think you would notice any differance between the two for that application.

The point is that while there is a differance in performance, it is so slight that it would take a great deal of non-stop hard use before you would really start to see it.

As an example. Sit down and start cutting 1/4" cardboard into 1" strips. Use two knives that are exactly the same. One with a S30V blade and one with a BG-42 blade. After about three hours you might start to see a differance. Compare that to what you REALLY do with your EDC pocket knife on a weekly basis and you will get my point.

Add to that the fact that most of use touch up the edges of our knives at least once a month. So the edges never get close enough to the point where we can even begin to notice any differance.

It would be like having two cars, one that can go 200mph and one that can go 220mph. What does it really matter if you never drive over 100mph? If all else is equal, it just is a matter of bragging rights. Fun to do, but not really that important day to day.
 
So I suppose then that partical metallugy and all that stuff those guys with pen packs in their shirt pockets put on data sheets that compare relative toughness, retension and other data means nothing to us and should just be over looked.(?).

RL
 
R.W.Clark said:
It would be like having two cars, one that can go 200mph and one that can go 220mph. What does it really matter if you never drive over 100mph? If all else is equal, it just is a matter of bragging rights. Fun to do, but not really that important day to day.
Click to expand...

the car that will do 220 will have the most power and will get up to 100 faster
:)
I can see where this is heading.. :)
some care some don't is the jest of it.

we have the different steels in my opinion for different applications.
440c will stand salt better than 154cm a bit tougher too..
I believe it won't hold a candle to 154cm as far as edge holding.
O1 is great for field re-sharpening. you pay price for what you're using it for.
I could make an axe to shave with but why??
I will continue to use a butter knife to butter my bread,
and the right tool for the job intended..
I see the point here ,,, to the EDU user,, but we as makers need to make the knife to the best we can,, as said. it's only as good as it's made.
a common Butter knife can out perform any grossly made Blade off any steel.

440C gets a bad wrap only because of the way it's heat treated
just my 2Cents...
 
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