Why do you like M4?
I understand quite a number of people here seems to like this steel. The only knife that I have now with this steel is the Contego, and I like it a lot. I am planning to buy more knives in M4, so I would like to learn more about the steel from you guys. Thanks in advance for the education.
By the way, I have heard that M4 easily rusts (at least some of my friends told me so) but this is not my (limited) experience. Given that the place I live is pretty humid I am pleasantly surprised.
By the way, I have heard that M4 easily rusts (at least some of my friends told me so) but this is not my (limited) experience. Given that the place I live is pretty humid I am pleasantly surprised.
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M4 has become one of my favorite steels. It takes and holds an awesome edge, yet is easier to sharpen than M390, and a whole lot easier than M2...never mind D2. 
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I hate that it has to be coated or it rusts, it just bothers me to have a knife that is so sensitive to the weather. This is a big deal to me as my EDC 941 with a D2 blade had significant pitting under the brass washers (not that I ever took it apart thus voiding the warranty), so the uncoated steel in the pivot can be weakened. 0 -
I have been carrying my M4 Ritter gips for some time and have not had an issue with rust. IMHO if you take the dang thang out ever day and use it then wipe it off you won't see any rust. And like Joe said, it takes a good edge and stays razor sharp longer.
Plus it's cooler than any other steel.
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M4 is just plain good stuff. I have never had rust issues so far either and have a few knives with M4. I have had more rust issues with D2. 0 -
i also agree about rust issues: often heard as a restrictive spec, but sincerely, when you use your knife there is no problem. maybe, for some uncoated blades, a patina could appears but that's only aesthetic.
the main reason for me to like M4 over any other steel is the edge retention and the ease to obtain a crazy razor edge.
the new heat treatment on the contego or on the forum rift make the benchmade'M4 even better than on the previous models0 -
M4 is a high speed tool steel - like M2 (edit: M2, not D2), but with more Vanadium added to the mix. Vanadium Carbides in the steel mean it will be harder and tougher and more heat-resistant than other steels with which you are already familiar. You get higher hardness, greater edge retention, and greater heat resistance (which can often be a factor in industrial cutting tasks).
If rust is a concern, consider M390 instead of M4.0 -
I like it because it can stand up to hard use and still retain its edge. 154CM can't do this quite as well. 0 -
I never found very much similarity between M4 & D2. There is quite a bit of similarity between M4 & M2. They both sharpen fairly easily, come to a keen edge and hold it like crazy. The biggest difference I've noticed lately was pointed out by Pascal, it's that the heat-treat on the newest models of M4 was increased and that has been a noticable improvement. What are we at now, a Rockwell of 61,or so?
That seems great for a knife, allowing it to still retain adequate toughness. Of course, when they use M4 strictly as a tool steel, they can run the Rc Hardness up even more.0 -
M4 is one of the best steels out there, in my opinion. It holds an edge forever and is fairly easy to sharpen. Rust has never been an issue for me. 0 -
If you want to make the most of your M4 blade, make sure it is sharpened at a sufficiently steep angle to take advantage of its ability to hold an edge.
Don't worry so much about hitting a certain degree of edge angle, just make sure that a ground edge is exposed that is at least as wide as the one on the new forum knife. It won't be quite as thick as a dime, but it will be 2/3 that thick...maybe a little more. In my experience, if you start cutting the edge as thick as a dime you might start running into chipping issues. I've had that happen on several steels and I've had to go back and give the knife a micro-edge to eliminate the chip and strengthen the edge.0 -
fastjan, i think the hrc reach 62-64 on the new bm's m4
an other thing i noticed about M4 is that even with a high hardness, the edge stays clean and razor; on other up-graded steels as m390, s90v ... i've experiment that a kind of micro-serrations can appear with use. not on my m4 blades ...0 -
Thanks, I couldn't remember what it was on the new ones. I did read that they often run the hrc to 65 for tool steel purposes.quote:Pasacal wrote...fastjan, i think the hrc reach 62-64 on the new bm's m4
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quote:Originally posted by something:
M4 is one of the best steels out there, in my opinion. It holds an edge forever and is fairly easy to sharpen. Rust has never been an issue for me.
I dont get it. Why am I hearing 2 different things
Some people say M4 is fairly easy to sharpen, then others say it is a B@@ch to sharpen. What are you guys using to sharpen it?.
Thanks.0 -
I've sharpened M4 on crock sticks, Sharpmaker, and an EdgePro. It's not hard to sharpen at all. It's a little harder to sharpen M390 with all that nasty chromium in it. It's waaay harder to sharpen D2. Sometimes S30V will give you fits too, but M4 likes to be sharpened. It also likes to be stropped.quote:Mashguy wrote...I dont get it. Why am I hearing 2 different things
Some people say M4 is fairly easy to sharpen, then others say it is a B@@ch to sharpen. What are you guys using to sharpen it?.
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quote:Originally posted by fastjan:
I've sharpened M4 on crock sticks, Sharpmaker, and an EdgePro. It's not hard to sharpen at all. It's a little harder to sharpen M390 with all that nasty chromium in it. It's waaay harder to sharpen D2. Sometimes S30V will give you fits too, but M4 likes to be sharpened. It also likes to be stropped.quote:Mashguy wrote...I dont get it. Why am I hearing 2 different things
Some people say M4 is fairly easy to sharpen, then others say it is a B@@ch to sharpen. What are you guys using to sharpen it?.
Cool. Thank you for the reply.0 -
GPknives.com has a Griptilian in M4, run of 300 if you're looking for more M4 
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The reason you hear different stories about rust is this. M4 is has 4% Chromium. Most steels that are classified as stainless have around 13%. 1095 carbon steel has 0% chromium and is just waiting to rust. So with 4% the M4 has some stainless qualities but not enough for "normal" levels of protection. If you live in humid/wet areas your mileage may be worse than others. If you cut wet things or acidic things and don't clean/dry the blade your mileage will be worse.
Here is a great web site about steels, this link is direct to the steel chart. You can see the chemical composition of different steels and also read about the affects of the elements in steel here.
http://zknives.com/knives/steels/steelchart.php
Also no one mentioned that BM uses CPM-M4. CPM means Crucible Particle Metallurgy (or Powder Metallurgy). Crucible is the brand name. Particle Metallurgy means the steel is made from powdered steel and sintered. In the end this produces finer, more uniformly distributed carbides, which are important to edge characteristics in knife steel. Plain M4 is made the old way, heat a blank of steel and forge it. For example BM uses 154cm steel, but as far as I know doesn't use CPM-154cm.
CPM-M4 in BM knives is a wonderful steel. The only drawback is somewhat limited stainless characteristics. If you want to leave it outdoors or cut lemons you will need to keep it oiled.
If you are knife nut you need at least one BM CPM M4 in your collection.0 -
quote:Originally posted by mashguy:quote:Originally posted by something:
M4 is one of the best steels out there, in my opinion. It holds an edge forever and is fairly easy to sharpen. Rust has never been an issue for me.
I dont get it. Why am I hearing 2 different things
Some people say M4 is fairly easy to sharpen, then others say it is a B@@ch to sharpen. What are you guys using to sharpen it?.
Thanks.
I guess it depends what you're comparing it too. compared to something like 440c or N680 it's a lot harder to sharpen, but compared to something like D2 it's pretty easy.0 -
True enough...or like me, I have 26 knives in my EDC drawer. 16 of those are either CPM M4 or M2. I keep a few stainless steel blades in there in case I'm going to do something that would naturally call for a stainless steel like cutting plants or working in salt water. I don't particularly like the stainless blades very much except for the fact that they are rust deterrent. For everything else they aren't as good, imo.quote:Geocyclist wrote...If you are knife nut you need at least one BM CPM M4 in your collection.
That being said, I've never had rust on any M4 or M2 knife and in total I probably have 25 of them.0 -
I like it because everyone else does. 0 -
quote:Originally posted by fastjan:
True enough...or like me, I have 26 knives in my EDC drawer. 16 of those are either CPM M4 or M2.
Are they all Benchmades? Do you mind sharing what models are they? Thanks.0 -
quote:Originally posted by archer:
I like it because every else does.
That's a rational reason, running with the herd...ROLMAO0 -
quote:Originally posted by Who Dares Wins:quote:Originally posted by archer:
I like it because every else does.
That's a rational reason, running with the herd...ROLMAO
yeah... not a good idea. Our country did that tuesday0 -
Yes, the ones I spoke of are all Benchmades:quote:Bchan77 wrote...Are they all Benchmades? Do you mind sharing what models are they? Thanks.
(2) Contego 810
M4 806
M2 805 - re-ground
(2) M4 950
(2) M4 520
(2) M2 710
M4 710
M4 Gaucho - re-ground
M4 760 (? the ones that were heavy tanto blades) re-ground
M2 CF Ares, re-ground
M2 835 Lock-back (I think that's the right #)
M4 Gold Grip
If I counted correctly that's 16.0 -
fastjan, nice collection! 0 -
no 525-1102's FJ? 0 -
Can M4 be bought in little bars like gold and silver?
Just asking.0 -
I've had them before, but sold em off. Just a little too short for my tastes.quote:Lightning asked...no 525-1102's FJ?
Just as a point of explanation though...when I put a knife with a 4" handle into a pocket that's 6" deep it just feels like I'm wasting 2" of pocket for no reason.0 -
Probably the reason for differing experiences with rust on M-4 is the environment. I've used an M-2 around salt water, and it will rust pretty actively in that environment. On the other hand, I've taken M-2 blades on hikes where it was used pretty regularly in the rain over several days, and nothing beyond a slight darkening of the edge occurred. Big difference between fresh water and salt water environment. Same would be true of differences in salt moisture depending on how you carry it, and how often you use it, etc. Bottom line is it will rust if you don't take care of it, but won't be a pain in the butt at all if you do. Good stuff. 0 -
quote:Originally posted by fastjan:
I've had them before, but sold em off. Just a little too short for my tastes.quote:Lightning asked...no 525-1102's FJ?
Just as a point of explanations though...when I put a knife with a 4" handle into a pocket that's 6" deep it just feels like I'm wasting 2" of pocket for no reason.
I can see that... but it doesn't work for me because I like to sit down every once in awhile. ... ok. quite often0
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