S30V vs M390 Toughness?

That's a funny thing to be curious about, as there is virtually no practical use that could come out of that knowledge.
 
RevDevil said:
At this point, I will hang onto them for a rainy day. I've had about a dozen people ask me over the years to sell one but it's my favorite Spyderco (tied with the Military). ;)
Click to expand...

Do you have a Military family portrait also? If so, show us for inspiration Rev!
 
Yes, I have a horrible picture. My apologies for the lack of quality. That too is an old outdated photo.
PzA2nxml.jpg
 
Ankerson has consistently found that M390 and its variants hold an edge better than S30V. It’s not clear to me why M390 has that edge because both carry 4 percent vanadium.

M390 has a higher alloy load (28.5 percent to 21.45 percent), so I’d expect S30V to be a little tougher, but that doesn’t seem to be the case, although both appear to be close in toughness.

Toughness reduces the tendency to chip, and from anecdotal posts on the forum, S30V seems far more chippy than M390, which would indicate a sizable advantage for M390 in terms of toughness.

But the charpy data — which are admittedly fragmented and scarce — would give M390 only a very small toughness advantage.


me2 has posted these values:
S30V - 38J @ 58-60?
M390 - 41J/sq cm @ 58? and 32J/sq cm @ 63 (unknown test method)

From CM Bushman’s charpy thread:
http://www.bladeforums.com/forums/s...ion-on-Charpy-C-Notch-Values?highlight=charpy

Steel-------Hardness-----Charpy C Ft. Lbs.

CPM-S30V.....@Rc58...........28
CPM-S35VN....@58Rc...........32
CPM-154......@60Rc............30
154CM..........@Rc58...........28
440C............@Rc58...........16
420HC...........@Rc58...........24
M390............@Rc60...........22
 
Last edited:
CPM-S30V toughness data (Charpy C-notch) can be had from Crucible, they list it as on par with 440C (~25J) unless you measure the transverse value (which no one does, it's too low): http://www.crucible.com/PDFs\DataSheets2010\dsS30Vv1 2010.pdf

CPM-20CV (Crucible's version of M390) is about the same but at 2-points higher hardness: http://cdna.terasrenki.com/ds/CPM-20CV_DuraTech-20CV_Datasheet_1.pdf

But M390 higher toughness data comes from an EU paper, doesn't use Charpy-C but gives comparative values for Elmax and S90V. http://www.kau.se/sites/default/files/Dokument/subpage/2010/02/26_349_359_pdf_19432.pdf
 
Twindog said:
M390 has a higher alloy load (28.5 percent to 21.45 percent), so I’d expect S30V to be a little tougher, but that doesn’t seem to be the case, although both appear to be close in toughness.

Toughness reduces the tendency to chip, and from anecdotal posts on the forum, S30V seems far more chippy than M390, which would indicate a sizable advantage for M390 in terms of toughness.
Click to expand...

Also anecdotal, but I've had better luck with S30V than M390/204P/20CV.

I no longer have my M390 Para 2, but at the time I had both it and my S30V model, so the blades were identical. Although the M390 generally lasted longer than the S30V, while the S30V tended to dull "smoothly", the M390 seemed to dull in phases as the edge would roll or microchip in places. So as long as I avoided that, it would hold its edge for quite a while. I saw the same thing with my 204P model.

But despite that, I don't necessarily think M390 is a chip risk. It does very well in certain applications, which is why I purchased a GSO 3.5 in 20CV just a few months ago. However, I just think people tend to underestimate S30V, especially in comparison.
 
I don't have any m390, but I have a few different knives w s30v and I've never had any issues with it being "chippy" at all. In my experience it has seemed very tough.
 
Does crucible have anything comparing them? If you got any solid info proving otherwise you should contact simplytoolsteels and tell them they don't know squat about steel and there info is wrong lol
chiral.grolim said:
Yeah, they should remove that chart, looks to be utter nonsense, not clear what they base any of the values on :thumbdn:
Click to expand...
 
shinyedges said:
Does crucible have anything comparing them? If you got any solid info proving otherwise you should contact simplytoolsteels and tell them they don't know squat about steel and there info is wrong lol
Click to expand...

Like every other steel chart of that type, it's incomplete at best and almost certainly misleading. Other than sweeping generalities, it really doesn't mean a whole lot more than, someone knows how to make a pretty bar graph. "All grades at 58-60Rc"? There can be very significant differences in almost any steel in that range, and (for instance) comparing D2 at 60Rc to CPM-154 at 58Rc is going to be way, way off from comparing them both at the same hardness.

Spend enough time looking at so-called charts like that and you can find one to suit nearly any "results" you want - whether it makes any sense or not is a whole other question...
 
shinyedges said:
Does crucible have anything comparing them? If you got any solid info proving otherwise you should contact simplytoolsteels and tell them they don't know squat about steel and there info is wrong lol
Click to expand...

See my post just before that one? It contains data sheets from Crucible on S30V and CPM-20CV. It looks like simplytoolsteel took they comparative transverse toughness comparison of S30V and such to 440C and pretended it was longitudinal toughness and kept the same proportions for only those steels, i.e. utter nonsense. Per crucible, S30V and S35VN and CPM-20CV, etc. all present about the same impact toughness as 440C but at a few points higher hardness (which is good, but nothing like what that graph pretends).
 
There is a lot of info and technical talk here. And i can't understand any of it. But my knife is pretty hard. Its pretty good at chopping' and it stays laser sharp forever.

On a serious note, they are 2 different steels created for good reasons both. In my little experience with s30v when it dulls it tends to dull without any chipping or rolling. The edge just kinda disappears but the geometry will allow it to keep slicing. I can't compare it to m390 because I just haven't gotten that steel yet.
 
james terrio said:
Like every other steel chart of that type, it's incomplete at best and almost certainly misleading. Other than sweeping generalities, it really doesn't mean a whole lot more than, someone knows how to make a pretty bar graph. "All grades at 58-60Rc"? There can be very significant differences in almost any steel in that range, and (for instance) comparing D2 at 60Rc to CPM-154 at 58Rc is going to be way, way off from comparing them both at the same hardness.

Spend enough time looking at so-called charts like that and you can find one to suit nearly any "results" you want - whether it makes any sense or not is a whole other question...
Click to expand...


Yeah, I wouldn't put too much stock in what the various charts say, or the data sheets for that matter as they don't represent or reference knife blades in the 1st place....

The data sheets represent what the steels were originally developed for, and that's not knife blades...

The sheets are for general reference......
 
So correct them is all I'm saying, I understand 2 points of hardness will have significant impact on each steel. You seem to have all the info so let them know there chart and steel info is crap and it pretends to be true lol I'm not taking this too seriously kinda seems like you are so if I ruffled your feathers over a chart it wasn't intended..
chiral.grolim said:
See my post just before that one? It contains data sheets from Crucible on S30V and CPM-20CV. It looks like simplytoolsteel took they comparative transverse toughness comparison of S30V and such to 440C and pretended it was longitudinal toughness and kept the same proportions for only those steels, i.e. utter nonsense. Per crucible, S30V and S35VN and CPM-20CV, etc. all present about the same impact toughness as 440C but at a few points higher hardness (which is good, but nothing like what that graph pretends).
Click to expand...
 
This might be incorrect but wasn't s30v originally created as a knife steel ? I thought I read it was one of the first steels created specifically for knives?
Ankerson said:
Yeah, I wouldn't put too much stock in what the various charts say, or the data sheets for that matter as they don't represent or reference knife blades in the 1st place....

The data sheets represent what the steels were originally developed for, and that's not knife blades...

The sheets are for general reference......
Click to expand...
 
according to crucibles chart s30v is four times more tough than 440c..... and it has 20cv as being the same as 440c. so wouldnt that mean s30v is tougher than 20cv? its right there on the charts you posted...
chiral.grolim said:
CPM-S30V toughness data (Charpy C-notch) can be had from Crucible, they list it as on par with 440C (~25J) unless you measure the transverse value (which no one does, it's too low): http://www.crucible.com/PDFs\DataSheets2010\dsS30Vv1 2010.pdf

CPM-20CV (Crucible's version of M390) is about the same but at 2-points higher hardness: http://cdna.terasrenki.com/ds/CPM-20CV_DuraTech-20CV_Datasheet_1.pdf

But M390 higher toughness data comes from an EU paper, doesn't use Charpy-C but gives comparative values for Elmax and S90V. http://www.kau.se/sites/default/files/Dokument/subpage/2010/02/26_349_359_pdf_19432.pdf
Click to expand...
 
shinyedges said:
This might be incorrect but wasn't s30v originally created as a knife steel ? I thought I read it was one of the first steels created specifically for knives?
Click to expand...

Yes. My understanding is, S30V came about by Crucible attempting to develop a stainless 3V. They didn't quite succeed.

shinyedges said:
You seem to have all the info so let them know there chart and steel info is crap and it pretends to be true lol I'm not taking this too seriously kinda seems like you are so if I ruffled your feathers over a chart it wasn't intended..
Click to expand...

I think you're missing the point. There are several different ways to measure "toughness" and "corrosion resistance" and so forth, and not all datasheets report the same methods. So even compiling/comparing DS's from different manu's doesn't always give us a true, clear picture of what we're looking at.

Some of us do take this stuff pretty seriously... sometimes because it's an important part of our livelihood. If you're more interested in lols, perhaps you would have more fun in Whine & Cheese. :)
 
This is straight from the crucible info you posted... notice it says 4 times tougher than 440c. Which would mean tougher than 20cv as well because crucible has 20cv listed as the same toughness as 440c.....

Toughness (Transverse Charpy C-notch Testing)
Grade Impact Energy
CPM S30V 10.0 ft. lbs.
154CM 2.5 ft. lbs.
440C 2.5 ft. lbs.
Although the longitudinal toughness for all three of these grades
is about 25-28 ft. lbs., the transverse toughness of CPM S30V is
four times greater than that of 440C or 154CM. These higher
transverse toughness results indicate that CPM S30V is much
more resistant to chipping and breaking in applications which
may encounter side loading. In knifemaking, its higher transverse
toughness makes CPM S30V especially good for bigger blades.

chiral.grolim said:
See my post just before that one? It contains data sheets from Crucible on S30V and CPM-20CV. It looks like simplytoolsteel took they comparative transverse toughness comparison of S30V and such to 440C and pretended it was longitudinal toughness and kept the same proportions for only those steels, i.e. utter nonsense. Per crucible, S30V and S35VN and CPM-20CV, etc. all present about the same impact toughness as 440C but at a few points higher hardness (which is good, but nothing like what that graph pretends).
Click to expand...
 
You must log in or register to reply here.
Back
Top