CPM 3V versus similar steels?

[WorkingEdge]

Hello

So I was looking into the Tuff and it's 3V steel. While trying to research the steel, I came across the usual heavy comparisons to Infi but once in a while to something called Sleipner. Can't find as much info on this steel. Any thoughts?

[Strong-Dog]

Super-tough S30V that will rust on you

[Donut]

Sliepner is pretty similar to D2. I think they tweaked D2 some. Lionsteel works with it a lot.

I have a DPx HEST Folder Milspec with it and a DPx HEAT Folder with it. It works pretty nice. It's pretty stainless, but does stain.

[phaust]

Per the manufacturer sleipner was an attempt to make something between d2 and a2, tougher than d2 but with more wear resistance than a2. I only have one knife in it but would say that's accurate; comparing to cpm-d2, it doesn't stay sharp as long and rusts maybe a bit easier. Not in the same wear-resistance class as my couple of knives in cpm3v either. I couldn't compare any of them in toughness.

Lionsteel is the only company I know of using it, and they have made what are **in my experience** (which is to say, not the ultimate word) some ridiculous claims about it, like that it outperformed m390 in their tests

[razorsharp]

Super tough steel probably comparible to s30v that will only patina or rust if abused. I can't make it rust under normal use. It also holds a fine edge really good

[michaelm466]

As mentioned above Sleipner is closer to CPM-D2, CPM-3V's equivalents are PD-1 and Z-ware.

[Franco G]

[TomAiello]

I saw a post from Sal a while back that the "Italians" (I think that's the Maniago factory that makes the Pingo and LionSpy) were trying to convince him to use Sleipner.

[WorkingEdge]

Thanks for the info. Sounds like it doesn't have any advantages over 3V.
wish Spyderco made more offerings in this stuff.

[Cliff Stamp]

Sounds like it doesn't have any advantages over 3V.

It has many :

-easier to grind
-easier to finish
-higher obtainable hardness

It could thus be used where 3V is rolling due to lack of hardness, or is not being used because it is to difficult to maintain (grind/finish).

[WorkingEdge]

It has many :

-easier to grind
-easier to finish
-higher obtainable hardness

It could thus be used where 3V is rolling due to lack of hardness, or is not being used because it is to difficult to maintain (grind/finish).

Cliff - if 3v is tougher and has better edge retention (not sure about that actually), how does higher hardness factor into performance of the knife? Or do I have it backwards and Sleipner has better edge retention due to higher attainable hardness?

[Cliff Stamp]

Cliff - if 3v is tougher and has better edge retention (not sure about that actually)

They are both very tough steels, I have not seen a significant amount of materials data which would argue that if you were having a problem with Sleipner and lack of toughness than 3V would be a solution. Calmax is what is recommended for that and that is basically a mid-carbon steel with alloy for air hardening.

In regards to edge retention, 3V has a higher abrasive wear than Sleipner however this doesn't translate into better edge retention directly because edges don't blunt by purely abrasive wear.



Here is the edge of a knife after cutting some cardboard, note that it has :

-rolling/denting
-fracture
-wear

Just increasing the wear resistance by adding more carbide could actually make it worse because if that was done alone it would drop the hardness (so it would roll/dent more) and the fracture toughness would go down as it would chip more.

If you are cutting fairly soft materials like natural ropes which don't significantly tend to chip/dent edges then 3V could have improved edge retention, however on materials which could tear out carbides, dent/roll edges, then Sleipner could be ahead.

In general saying one steel has better/worse edge retention than another is like saying a running shoe is better than a snowshoe, it depends on where and when you are doing the running.

[WorkingEdge]

Cliff - the problem is just as I thought it might be...I simply know too little!

For clarification (ignoring influences of design, heat treat, etc):

Hardness would affect rolling / denting.
Toughness would affect fracture.
Carbide volume would affect wear.

Thanks as usual.

[Cliff Stamp]

Hardness would affect rolling / denting.
Toughness would affect fracture.
Carbide volume would affect wear.

Yes, but not exactly.

Hardness affects rolling but not the gross hardness. You can have a blade which tests harder than another but the edge actually has less resistance to rolling.

Blades are not made of uniform materials, the steel is a complex blend of phases all of different micro-structures and properties. Hardness is a very poor indication of anything, if it is all you have then it is all you have, but never try to take more from it than very coarse estimates and you can't tell much about edges.

Consider this :

Blade A :

-80% martensite at 66 HRC, the rest is very soft phases

Blade B :

-95% martensite at 60 HRC, the rest (minor amount) is soft phases

Both of these will show ~59 HRC on a standard hardness test, but they will behave very differently. The first blade will show much more dramatic edge roll and even edge chipping.