What can you tell me about M4 steel?

[aquaman67]

With the onslaught of M4 bladed Paramilitary 2's shipping out I thought it would be a good idea to discuss the care of M4. I myself have never had an M4 knife.

I know M4 will patina - but does it have to? Is there any way to keep it "clean" (patina free)?

How easily does it rust?

If I need to keep it oiled, what oil do you recommend. Mineral oil?

Thanks in advance. I'm sure we a about to get a lot of new M4 owners.

 

[Jason B.]

M4 will patina but not like a true carbon steel, I would say it's a little more like D2 in its rust/patina resistance. The Patina is a natural protective oxide layer so it's something you actually want to happen.

You could keep it at bay with mothers mag polish and a rag but you would need to do this daily. I would just keep it dry, keep it sharp and use it daily.

 

[loonybin]

Eezox will work well for the blade, or a wax, but naked CPM-M4 is going to patina to some degree unless you turn rust removal and protection into your religion and become a devoted follower.

The patina is actually a good thing, which is why so many folks force a patina on the knife in a way that is more on their terms than nature's.

 

[aquaman67]

Thanks for the responses so far.

Patina won't bother me. But a friend of mine who is new to knives (my fault) will probably want something in M4 is absolutely anal about 'imperfections'. I'm going to steer him away from it. I don't think he will understand or appreciate the uniqueness of M4.

 

[Chris "Anagarika"]

My sweat is corrosive, as much as mirror bevel of my GB1 pitted, and recently found one dot on my E4 ZDP (on the FFG, not the bevel). It occurred only if I walked a lot outside and sweating while the knife is in my RFP.
No brown/orange rust, simply pitted directly . So it depends.

Now I ensure the ZDP has light oil wipe before putting it into my pocket and the GB1 is heavily peppered with patina (using antiseptic body wash liquid) and now also lightly wiped with oil (just baby oil). Haven't seen it reoccurring. :thumbup: