The "Ask Nathan a question" thread

Nathan the Machinist

KnifeMaker / Machinist / Evil Genius
Moderator
Knifemaker / Craftsman / Service Provider
Joined
Feb 13, 2007
Messages
11,596
Since it's confirmed that Magnacut will be one of the steels used in upcoming CPKs, could you comment on the results of your testing?

Does it really come close to a stainless 4V?

So far (for me), no, it really isn't quite "come close" to a stainless 4V. You're probably not going to see this used in Bladesports events. It is, however, very good.

People don't understand how good optimized 4V can really be. It will outperform Delta 3V in many ways and that's why we use 4V on our competition cutters. It rusts, it chips, and it fails catastrophically (Matt Gregory has broken one of my 4V choppers in use and he needs help breaking dry spaghetti), but it has outstanding edge stability, gross durability and the ability to support thin geometry in very rough use that would bend a similar section in Delta 3V or Infi. I don't think anyone will duplicate the properties of 4V in some of these fringe applications in a stainless. That said, it runs circles around other stainless CPM materials like S30V etc. Magnacut is soooo good. But no, in my opinion it isn't 4V.

But, what it is: it is very stainless, it wears well, and (very importantly) it has the edge stability to remain sharp in regular use where other stainless would fail due to mushy/chippy edge failure and something low carbide like AEBL would dull from regular abrasive wear. And this is just with a relatively normal heat treat, we didn't receive enough material to really optimize it yet.

Here are some comparative examples of Magnacut vs Delta 3V. Same pattern, same edge geometry same 16D nail. Delta 3V on the top, Magnacut at HRC 62.5 on the bottom

4Qzhd3q.jpg


b9JH8gq.jpg


at the moment D3V outperforms Magnacut at this particular task and 4V will outperform D3V in this nail chop. So far Magnacut isn't there yet. However, that's not really a fair comparison yet because we haven't finished our homework on the HT.

That is an industry standard HT Magnacut blade, and the industry standard heat treat that Larrin Larrin Larrin developed is much better than the approach specified in the datasheet for 3V and 4V. I don't know if there is a lot of room for improvement (although you know we'll try). That's aust 2050, plate quench, LN tempers at 350. Should yield 62 and yielded 62.5. I haven't Mc-Deltaed it yet though.

Right now, one of my biggest concerns is the low tempering temperatures. My 4V is much harder than that with a higher temper. For a number of reasons I won't go into here, I'm not a big fan of tempering under 400. I believe there are some potential problems with that. We have a lot of homework to do still but our preliminary results are good enough I'm comfortable using this material in upcoming work. Even with no improvements it is better than the other stainless options out there and it's possible that we may be able to squeeze a little more out of it.

Edit to add: this level of stainlessness at this hardness is witchcraft. I suspect Larrin is literally a genius. If you've heard the story how the steel actually came to exist you'll know that's not much of an exaggeration. I know the steel was developed for cutlery but I expect it would also have applications in things like exhaust valves, ball bearings and tool a die components such as mold cavities and extruder screws for corrosive materials like PVC. People don't understand this is not just another variation of 440C like everything else, it is a revolutionary material that deviates from its predecessors. It is truly novel.
 
Last edited:

Blues

hovering overhead
Staff member
Super Mod
Joined
Oct 2, 1998
Messages
26,911
Interesting, Nathan...I'm not quite sure how to catalog or quantify those results. (And I realize this is all preliminary.)

Putting aside its stainlessness...if that's a term...and just going by perceived performance to this point...what steel would you most liken it to?

Would Cru-Wear be in the ballpark? It sounds like a great steel for those requiring a stainless blade...but not necessarily for raw performance (yet).

I'm guessing it would underperform M4 in raw cutting ability, and 3V in toughness so that's why I'm asking about Cru-Wear as that happy medium.

Close? Or not yet determined?
 

bluemax_1

Gold Member
Joined
Jan 17, 2014
Messages
2,007
So far (for me), no, it really isn't quite "come close" to a stainless 4V. You're probably not going to see this used in Bladesports events. It is, however, very good.

People don't understand how good optimized 4V can really be. It will outperform Delta 3V in many ways and that's why we use 4V on our competition cutters. It rusts, it chips, and it fails catastrophically (Matt Gregory has broken one of my 4V choppers in use and he needs help breaking dry spaghetti), but it has outstanding edge stability, gross durability and the ability to support thin geometry in very rough use that would bend a similar section in Delta 3V or Infi. I don't think anyone will duplicate the properties of 4V in some of these fringe applications in a stainless. That said, it runs circles around other stainless CPM materials like S30V etc. Magnacut is soooo good. But no, in my opinion it isn't 4V.

But, what it is: it is very stainless, it wears well, and (very importantly) it has the edge stability to remain sharp in regular use where other stainless would fail due to mushy/chippy edge failure and something low carbide like AEBL would dull from regular abrasive wear. And this is just with a relatively normal heat treat, we didn't receive enough material to really optimize it yet.

Here are some comparative examples of Magnacut vs Delta 3V. Same pattern, same edge geometry same 16D nail. Delta 3V on the top, Magnacut at HRC 62.5 on the bottom

4Qzhd3q.jpg


b9JH8gq.jpg


at the moment D3V outperforms Magnacut at this particular task and 4V will outperform D3V in this nail chop. So far Magnacut isn't there yet. However, that's not really a fair comparison yet because we haven't finished our homework on the HT.

That is an industry standard HT Magnacut blade, and the industry standard heat treat that Larrin Larrin Larrin developed is much better than the approach specified in the datasheet for 3V and 4V. I don't know if there is a lot of room for improvement (although you know we'll try). That's aust 2050, plate quench, LN tempers at 350. Should yield 62 and yielded 62.5. I haven't Mc-Deltaed it yet though.

Right now, one of my biggest concerns is the low tempering temperatures. My 4V is much harder than that with a higher temper. For a number of reasons I won't go into here, I'm not a big fan of tempering under 400. I believe there are some potential problems with that. We have a lot of homework to do still but our preliminary results are good enough I'm comfortable using this material in upcoming work. Even with no improvements it is better than the other stainless options out there and it's possible that we may be able to squeeze a little more out of it.

Edit to add: this level of stainlessness at this hardness is witchcraft. I suspect Larrin is literally a genius. If you've heard the story how the steel actually came to exist you'll know that's not much of an exaggeration. I know the steel was developed for cutlery but I expect it would also have applications in things like exhaust valves, ball bearings and tool a die components such as mold cavities and extruder screws for corrosive materials like PVC. People don't understand this is not just another variation of 440C like everything else, it is a revolutionary material that deviates from its predecessors. It is truly novel.
Thanks for that. Been waiting to hear your impressions on it.
 
Joined
Jun 12, 2010
Messages
799
Nathan,
Since the last of the K18's is finally done and the first of the UF2'S are starting to ship !...
Have any double edge fighter's been worked on or finished ?... also since the K18s are finished does this mean that you'll have more time to put towards the rest of the UF2 pre-orders and also try to tweak the heat treatment for magnacut to where you are satisfied with your own heat treatment for magnacut? Thanks for your time...

Frank Cervantes aka FRC505
 

Casinostocks

Factotum
Gold Member
Joined
Mar 20, 2016
Messages
12,104
Will you reconsider doing another CPK in 4V if and when the opportunity comes along when such blade merits the steel? I'm old fashioned (let's say as stubborn as an old mule) and can't see myself getting into the Magmawhatever craze du jour, although I believe that if anyone can optimize it to a sick level, it'd be none other than you. Now with all the pleasantries and arsekissing aside, please think about a CPK in 4V before I kick the fucketbucket!
 

mb>

Gold Member
Joined
Sep 24, 2014
Messages
2,965
To the stainless property of Magnacut…I was surprised to see it is going to be released in Spyderco’s salt line. That’s saying something. That’s been mostly H1 and more recently LC200N…big shoes to fill in that regard. And a welcome upgrade in edge retention.

Will be exciting to see the McMagnacut delta’d up!
 
Top