M390 super steel?

[Premiumsteel]

M390 is available in the US, with a number of sizes to be stocked soon. There is stock now in 4.3mm (.168) in Rialto, CA not far from you

 

[Joshua J.]

From the impressions I've read and looking at the chemistry specs, I'd say it's a good improvement on S30V.
Still doesn't touch S110V, ZDP-189 or M-4 though.

 

[antonio_luiz]

H1 is rust proof steel.It can be left in salt water for years and not rust.It is the only rust proof steel on the market right now,and spyderco is the only production company that uses it at the moment.

Has X15TN been discontinued?

 

[KarlMaldensNose]

The Kershaw Volt will use Bohler M390. It should be out in Feb.

http://www.kershawknives.com/productdetails.php?id=518&brand=kershaw

The Kershaw Speedform will use Uddeholm EL-Max another so called super steel that is new to me.

http://www.kershawknives.com/productdetails.php?id=517&brand=kershaw

I checked out both of those links and was confused. Both of these so-called super steels are used with CPM D2 in composite blades. But I can't tell from the info or pics what steel is used for the edge. You'd think it would be the Bohler M390 and Uddeholm EL-Max on the Volt and Speedform respectively. If that's the case, why would Kershaw use CPM D2 as the "filler" steel. I know CPM D2 is not expensive and its use as filler works in that sense, but it isn't very tough, which I thought was an important characteristic of the filler steels in composite blades. Does my post make sense? I think I even lost myself.

 

[cotdt]

I checked out both of those links and was confused. Both of these so-called super steels are used with CPM D2 in composite blades. But I can't tell from the info or pics what steel is used for the edge. You'd think it would be the Bohler M390 and Uddeholm EL-Max on the Volt and Speedform respectively. If that's the case, why would Kershaw use CPM D2 as the "filler" steel. I know CPM D2 is not expensive and its use as filler works in that sense, but it isn't very tough, which I thought was an important characteristic of the filler steels in composite blades. Does my post make sense? I think I even lost myself.

It's because CPM-D2 can heat treat at the same temperatures as the M390/EL-Max. It could also be to create the contrast though I'm not sure about that. Barring those reasons, I'm not sure why they would pick CPM-D2.

 

[The Mastiff]

I checked out both of those links and was confused. Both of these so-called super steels are used with CPM D2 in composite blades. But I can't tell from the info or pics what steel is used for the edge. You'd think it would be the Bohler M390 and Uddeholm EL-Max on the Volt and Speedform respectively. If that's the case, why would Kershaw use CPM D2 as the "filler" steel. I know CPM D2 is not expensive and its use as filler works in that sense, but it isn't very tough, which I thought was an important characteristic of the filler steels in composite blades. Does my post make sense? I think I even lost myself.

The M390 and El Max are used in the edges, CPM D2 used for the spines. I'm sure there are more reasons than just this one but I know this has to be taken into account.

The heat treat cycles have to be similar or close. That's a no brainer. OIf one steel got scorched while the other one was being treated at the correct temp. it would ruin the whole blade.

I've heard chemistry is important too for whatever reasons but I'll leave that to the experts.

Premium steel, thanks for the update. When you get the other sizes in stock you might want to update as these steels look to be pretty nice performance wise. The similar 20CV is becoming pretty well known and has a pretty good reputation. I like it as a user steel and find it takes a nice edge, and holds it too.


Edit: You beat me to it while I was typing my 12 wpm. Thanks Cotdt.

 

[cotdt]

Edit: You beat me to it while I was typing my 12 wpm. Thanks Cotdt.

Hehe. I'm assuming that the two steels are welded together before the heat treat. If it is welded together after the heat treat then they could pick a tougher steel for the spine like 420HC.

 

[Gator97]

To be honest I do not understand using CPM D2 as a blade spine material.
CPM D2 on its own is a perfectly good steel to be used in light at cutters at higher hardness. It's the same thing as using ATS-34 as cladding for ZDP-189 steel. Why? It's more expensive than 410 or something similar.

M390 is essentially the same steel as Duratech 20CV, except that it has higher Si content, and more metallurgical experienced forumites could explain influence of Silicon on the alloy better than me.

All that based on M390 vs. DuraTech 20CV vs. CPM D2 steel composition comparison

 

[SPXTrader]

To be honest I do not understand using CPM D2 as a blade spine material.

As mentioned, the steels share a common HT process. You just can't go throw 2 steels together and expect them to work. Its a science, and Kershaw seems to have it figured out.

 

[A_Blade_Afficionado]

As mentioned, the steels share a common HT process. You just can't go throw 2 steels together and expect them to work. Its a science, and Kershaw seems to have it figured out.

It's also for etching purposes. D2 takes a nice dark etch (Ti Tyrade, CB JYD) that gives a contrast unattainable with your typical steels used for cladding (410, Sandvik 13C/14C, 420j, etc) so it's a necessary choice for the desired etch.

 

[Gator97]

I see. I missed same HT part somewhere.

 

[tjsulli790]

As mentioned, the steels share a common HT process. You just can't go throw 2 steels together and expect them to work. Its a science, and Kershaw seems to have it figured out.

Why throw 2 steels together in the first place? I don't see any reason that M390 can't work fine by itself.

 

[Gator97]

As mentioned, the steels share a common HT process. You just can't go throw 2 steels together and expect them to work. Its a science, and Kershaw seems to have it figured out.

Actually, I have another question.
Shallot was ZDP-189 edge + 14C28N spine. ZDP-189 is rated at 63-64HRC, and I'm not to sure 14C28N can be hardened to that level.
So, apparently those two are HTed apart and then "thrown together"...
In that case I doubt there is much of a science involved.

 

[Phillip Dobson]

Why throw 2 steels together in the first place? I don't see any reason that M390 can't work fine by itself.

If I remember correctly, the Speedform II will have a blade of solid Elmax. I think the biggest reason for a composite blade is appearance.

 

[SPXTrader]

Why throw 2 steels together in the first place? I don't see any reason that M390 can't work fine by itself.

Cost. A full blade of ZDP is a lot more expensive than one using it as a cutting edge.

Actually, I have another question.
Shallot was ZDP-189 edge + 14C28N spine. ZDP-189 is rated at 63-64HRC, and I'm not to sure 14C28N can be hardened to that level.
So, apparently those two are HTed apart and then "thrown together"...
In that case I doubt there is much of a science involved.

14C can be run at those levels. I's not the preferred hardness for a cutting edge, but for a spine it works well.

 

[Joshua J.]

Actually, I have another question.
Shallot was ZDP-189 edge + 14C28N spine. ZDP-189 is rated at 63-64HRC, and I'm not to sure 14C28N can be hardened to that level.
So, apparently those two are HTed apart and then "thrown together"...
In that case I doubt there is much of a science involved.

Potential hardness has almost as much to do with chemistry as heat treat.

For example, if a steel type doesn't have enough carbon it doesn't matter what you do, it won't get very hard. You can heat treat two steel types exactly the same and get very different results. ZDP-189 is a powder metal where 14C28N is not, ZDP-189 inherently has far more potential due to its alloy content, which would be impossible to get in a cast ingot steel (which 14C28N is).

IIRC the different steel types have to match in thermal expansion, steel gets bigger when heated to extreme temperatures.

 

[Joshua J.]

Also remember that the cost of grinding is very important. The more soft metal you can have on the blade the easier it will be on your machines.

 

[cotdt]

Actually, I have another question.
Shallot was ZDP-189 edge + 14C28N spine. ZDP-189 is rated at 63-64HRC, and I'm not to sure 14C28N can be hardened to that level.
So, apparently those two are HTed apart and then "thrown together"...
In that case I doubt there is much of a science involved.

That sheds some light on things. Isn't ZDP-189 heat treated in Seki Japan? So it does seem like ZDP-189 and 14C28N portions are heat treated separately. They both get heat treated in the ~1900F range so they can easily be heat treated together, but it doesn't seem like they are because of ZDP-189's proprietary heat treat.

It seems like they are just using ZDP and D2 to receive the darker etching.

 

[tjsulli790]

Cost. A full blade of ZDP is a lot more expensive than one using it as a cutting edge.

I was more on the topic of M390 and how the Volt uses it as a composite blade with CPM-D2. CPM-D2 isn't exactly a cheap steel, any steel that is formed from the CPM process should run a little high in price. In the case of the Volt I think Mr. Dobson is correct about it being for looks. No doubt it does look very cool, but I just don't see where it is necessary, from a performance standpoint, to produce M390 in a composite blade. And if it means having to use CPM-D2 has a secondary steel, there shouldn't be significant cost saving.

 

[2brothers]

That sheds some light on things. Isn't ZDP-189 heat treated in Seki Japan? So it does seem like ZDP-189 and 14C28N portions are heat treated separately. They both get heat treated in the ~1900F range so they can easily be heat treated together, but it doesn't seem like they are because of ZDP-189's proprietary heat treat.

It seems like they are just using ZDP and D2 to receive the darker etching.

Yes, ZDP-189 is treated in Japan. But it is also heat treated by Kershaw in the U.S. The only manf. here (I believe) allowed to do so.

No doubt it does look very cool, but I just don't see where it is necessary, from a performance standpoint, to produce M390 in a composite blade. And if it means having to use CPM-D2 has a secondary steel, there shouldn't be significant cost saving.

It really has nothing to do with being necessary or not.
They still paint cars blue. Why? It's not necessary. See what I mean?
Kershaw is just showing what can be done. Something different. A new choice at the sales counter.