Opinions on M4

[jackknifeh]

I've read off and on in this forum that people like M4 steel. I just read a thread called "Is this normal for M4?". There was one post that claimed M4 hed very good edge retention and a couple of comments stating the same. I have a knife on pre-order (Manix 2) with an M4 blade and would appreciate any quick comments about M4. My main concern is edge retention but since it isn't a stainless steel corrosion is another concern but already knowing this I know lubrication will be important for me. I've heard it is not a true carbon steel either.

Thanks,
Jack

[The Mentaculous]

It's a tool steel (about 4% Cr if I remember correctly, while carbon steel has little or no Cr), and from all the reports I've heard, it has phenomenal edge retention. Particularly the qualities of wear resistance and toughness far exceed S30V and even ZDP-189 from what I hear.

I'm looking to get a Gayle Bradley probably next week, so I can finally try it out myself. But at 62-65 Rc, 4% Vanadium, something like 1.5% carbon and 5% tungsten, I expect it to perform very well, with the only real drawback being corrosion resistance.

[jackknifeh]

It's a tool steel (about 4% Cr if I remember correctly, while carbon steel has little or no Cr), and from all the reports I've heard, it has phenomenal edge retention. Particularly the qualities of wear resistance and toughness far exceed S30V and even ZDP-189 from what I hear.

I'm looking to get a Gayle Bradley probably next week, so I can finally try it out myself. But at 62-65 Rc, 4% Vanadium, something like 1.5% carbon and 5% tungsten, I expect it to perform very well, with the only real drawback being corrosion resistance.

What you said here is about what I've heard before. This morning I've found two threads "Is this normal for M4?" and "Anyone here with gayle Bradley with date code JJ?". Both state concerns about edge retention on the M4 steel. They only mention the Gayle Bradley since this is the only folder Spyderco has that has ever used this steel that I know of. I'm now concerned because I have a Manix 2 w/M4 on pre-order and should be available in the next couple of weeks. My anticipation and expectation of this knife is as high as any knife I have ever decided to buy. Since I'm getting a different model knife I think I can assume the blades would have been made at different times and had a different heat treating than the Gayle Bradley. Some have mentioned that possibley the problem some people are having with their GB is bad heat treat during a batch of blades. I have no idea.

Jack

[toomzz]

Have 2 Bradleys. They are the first M4 knives I have. Great steel, great edge retention, but easily to resharpen. Stains pretty quickly, but IMHO that's ok. Viva la Patina! First it turns a little reddish brown, after that the patina becomes dull grey-white. I use ballistol (food-safe) to oil the blade every now and then to prevent eventually pitting.
Get an M4 blade (if it is treated correctly). I read the threads about the rolling and chipping edges, but haven't experienced any trouble yet.
To make myself fully clear; I am a HARDTIME USER, no showcase-dude with white cotton gloves :D

Cheers, stay safe!
Tomas

[unit]

If you like using a knife the way your grandfather did you will love M4. That is...you take care of your stuff and don't let it rust excessively (that is a lot easier than some make it seem BTW) and use it to do ALL sorts of things, it will impress the heck out of you. It is fantastic stuff. The problems reported are few and I have yet to hear official reports of actual problems with HT. Some could be sharpening related? If there is a downside, it is that M4 is not as easy to sharpen as your grandpas knife, but it will needs it far less often and Spyderco will do a fine job of it for you if need (free).

[jackknifeh]

If you like using a knife the way your grandfather did you will love M4. That is...you take care of your stuff and don't let it rust excessively (that is a lot easier than some make it seem BTW) and use it to do ALL sorts of things, it will impress the heck out of you. It is fantastic stuff. The problems reported are few and I have yet to hear official reports of actual problems with HT. Some could be sharpening related? If there is a downside, it is that M4 is not as easy to sharpen as your grandpas knife, but it will needs it far less often and Spyderco will do a fine job of it for you if need (free).

Thanks Unit. This is reassuring. I do take very good care of all my tools. I like your reference to the grandfather mindset. My father is grandfather age to a lot of people on this forum and he ALWAYS took care of his stuff. He even gets his oil in the car changed every 3000 miles (or whatever the suggestion is now days). He is still kicking though and that is good if you consider that I am now a grandfather (check out my avatar).

I'm really really looking forward to the Manix 2 with M4 and FFG. If I like it as much as I hope to I'll probably get a second one if they last. It is one of those limited edition knives. In fact if I like it you will know because I'll post a thread telling everyone how terrible it is so no one will buy my "second" one. :D :D Seriously though, the posts this morning have me concerned a little but I feel I'll end up getting the knife because if the negative experiences a few people have had was the norm M4 wouldn't be praised like you just did. I hope the people who have had problems get them resolved. If it is a sharpening issue I know that will be resolved and if it is actually a "bad batch" of blades I believe Spyderco will take care of that as well.

Jack

[unit]

Precisely Jack. If there is a problem it is a strange thing. M4 is fantastic period. This does not mean it is impossible to get a defect, but it would be both rare and taken care of by Spyderco. Fear not!

There are way too many serious users using thus steel for SERIOUS business for there to be some Achilles heel of the alloy that we are only discovering in the past week or so. Nothing is perfect but....

There could be a bad batch of steel or HT but until that is confirmed I will sit back on my own observations and use data. I now own several m4 knives and it is rapidly becoming a common thread in my collection. I also commissioned a custom in this steel. Can I possibly convey more that I think this steel is fantastic?

[The Mentaculous]

BTW, it should be noted that while there are 2 threads about it on the main page, one was bumped to the top by the creator of the recent thread, but was posted over a month ago. Those are the only 2 existing reports of this problem, and strangely enough, both of them reprofiled their knives to a nearly identical, somewhat obtuse angle. So you never know, like Unit said, it could be a sharpening issue that they didn't detect. I'm confident enough that I will be buying a GB soon, probably coming from the same batch. If I experience problems, I know I can trust spyderco to fix it. I'm really looking forward to trying out this steel, which, even just judging by the chemistry, looks fantastic.

I do hope that the original person to post about this issue gives an update on how Spyderco responded, and if they said what the issue was. I'd be very interested to hear what the Rc hardness was on the knife in question.

[jackknifeh]

Precisely Jack. If there is a problem it is a strange thing. M4 is fantastic period. This does not mean it is impossible to get a defect, but it would be both rare and taken care of by Spyderco. Fear not!

There are way too many serious users using thus steel for SERIOUS business for there to be some Achilles heel of the alloy that we are only discovering in the past week or so. Nothing is perfect but....

There could be a bad batch of steel or HT but until that is confirmed I will sit back on my own observations and use data. I now own several m4 knives and it is rapidly becoming a common thread in my collection. I also commissioned a custom in this steel. Can I possibly convey more that I think this steel is fantastic?

Unit, just to make sure I understand you, YOU LIKE M4! :D Thanks for the reassurance.

BTW, it should be noted that while there are 2 threads about it on the main page, one was bumped to the top by the creator of the recent thread, but was posted over a month ago. Those are the only 2 existing reports of this problem, and strangely enough, both of them reprofiled their knives to a nearly identical, somewhat obtuse angle. So you never know, like Unit said, it could be a sharpening issue that they didn't detect. I'm confident enough that I will be buying a GB soon, probably coming from the same batch. If I experience problems, I know I can trust spyderco to fix it. I'm really looking forward to trying out this steel, which, even just judging by the chemistry, looks fantastic.

I do hope that the original person to post about this issue gives an update on how Spyderco responded, and if they said what the issue was. I'd be very interested to hear what the Rc hardness was on the knife in question.

Ok guys, I am back to very eagerly waiting for the M2/M4 to be released with no worries. Life is good again. :D

Jack

[Sequimite]

In terms of taking and holding a sharp edge, my M4 Mule is the best knife I have(don't use the 52100 Mule enough for a fair comparison). If you look at the cutting competitions I haven't heard of any knives being used other than M4 or 52100. Real world competition is the best indicator IMO.

[unit]

In terms of taking and holding a sharp edge, my M4 Mule is the best knife I have(don't use the 52100 Mule enough for a fair comparison). If you look at the cutting competitions I haven't heard of any knives being used other than M4 or 52100. Real world competition is the best indicator IMO.

True! I think some have tried a few other steels, but M4 seems to be the most seen steels at these competitions (perhaps 10 to 1?).

I took my kids to swim lessons this morning...thought I would conduct a little test on this steel while I was there. I dipped the blade in the indoor pool (chlorinated water) then shook it off. I will let you know how it turns out....

I dipped it to approximately the depth indicated by my thumb nail on the blade.


More later...

[jackknifeh]

True! I think some have tried a few other steels, but M4 seems to be the most seen steels at these competitions (perhaps 10 to 1?).

I took my kids to swim lessons this morning...thought I would conduct a little test on this steel while I was there. I dipped the blade in the indoor pool (chlorinated water) then shook it off. I will let you know how it turns out....

Very interested in chlorinated water test. Does the blade have any corrosion preventative on it now (or before you dunked it)? Tuf-Glide is what I use. Did yours have anything like that?

Thanks,
Jack

[unit]

Very interested in chlorinated water test. Does the blade have any corrosion preventative on it now (or before you dunked it)? Tuf-Glide is what I use. Did yours have anything like that?

Thanks,
Jack

Nope! I might treat it with whatever oil I find laying around after this test is over...but I do not routinely oil up my knives that I carry daily. I use them and if I see schmutz on the blade I wipe it on my shirt.

I frequently use my EDC to cut my lunch, and while the knife is never "clean", I rarely introduce oil into the flavor mix :D

We are going on an hour now...I have nothing worth photographing yet.

For the record, I do not recommend doing this to any knife, but I am pretty sure I have the skills needed to take care of the surface rust that I expect this knife to eventually get....and I am not going to let things progress to deep pitting rust (it simply will not happen because this knife is going to be cutting some cheese and other oily foods later today). I am not trying to make it rust...just intend to demonstrate that if you use your knife like I do, rust is not going to be a big concern...

[jackknifeh]

Nope! I might treat it with whatever oil I find laying around after this test is over...but I do not routinely oil up my knives that I carry daily. I use them and if I see schmutz on the blade I wipe it on my shirt.

I frequently use my EDC to cut my lunch, and while the knife is never "clean", I rarely introduce oil into the flavor mix :D

We are going on an hour now...I have nothing worth photographing yet.

For the record, I do not recommend doing this to any knife, but I am pretty sure I have the skills needed to take care of the surface rust that I expect this knife to eventually get....and I am not going to let things progress to deep pitting rust (it simply will not happen because this knife is going to be cutting some cheese and other oily foods later today). I am not trying to make it rust...just intend to demonstrate that if you use your knife like I do, rust is not going to be a big concern...

Just for anyone who cares, I used Tuf-Glide on an very inexpensive folding knife I used to have then put it outside on a tree branch for a couple of weeks. It just sat there getting dew on it every morning not to mention being rained on and had no problems with it. It opened and closed just as easy as before and didn't have any rust on it that I remember and if it did have any I would have remembered it. Like you said Unit, this is not a good practice.

Jack

[Tsujigiri]

Edge retention and toughness are fantastic. It also seems to resist rust, but will patina fairly easily.

[Handwrecker]

CPM-M4 is great stuff. Quite tough and will hold a killer edge for a very long time. It seems to touch up very nicely even though there's so much vanadium and it's at such a high RC level. Probably due to the CPM process.

I've been carrying a Gayle Bradley for about 2 months straight now, and I'm impressed. No rust or real patina, despite lack of oiling and being used to cut up citrus fruit and anything else I come across. I have a little darkening/loss of luster on the thumb ramp, and specks (almost too small to see) next to the Spyderco logo. Definitely not red rust. It may not be a "stainless" but it isn't anything like a true carbon steel. In fact, I've gotten more staining on S30V from my bad tap water and VG10 from sweat than I have from carrying and using the M4.





Sorry for the cell pics, just trying to show sun on the blade, it hasn't darkened up much yet.

[yablanowitz]

I have 2 M4 Mules, a Gayle Bradley and an M4 Military that I have carried and used at work with none of the issues seen in those threads. My guess would be a burr from the rebevelling process is the real culprit. M4 is tougher than the average bladesteel, and a burr can be hard to remove.

Dipping the blade in pool water will probably do nothing to it. The only rust I've seen on any of my M4 knives was on the handle of one of my Mules where the paracord wrap got wet. The cord kept the moisture against the steel long enough to cause rust to form. Big whoop.

[JNewell]

Not sure what you'll find about the pool water. We had an in-ground pool for years and the ferrous materials stored in the shed with the powdered chlorine corroded at a frightening rate. Obviously the chlorine strength in the pool is much more diluted.

I've read (I forget where) that there is something about the powder process that results in somewhat greater corrosion resistance than otherwise equivalent conventional ingot metal. That would be consistent with the uneven (literally; sort of splotchy) results people often get when creating rust, excuse me I mean "patina," on CPM-M4 blades.

[unit]

Yeah, basically I found nothing from the chlorine/water. I was not going to suspend my life and wait for things to happen. I came up with a challenge for myself today, and selected this knife for the challenge, and probably ruined the "test" in the process. I wanted to do some carving, and the BG seemed like the best choice for the challenge, so I did it. Up to that point there was NOTHING to report.

Here is the thread discussing that activity:
http://spyderco.com/forums/showthread.php?t=48671

Something I did discover after I was finishing the carving and it sort of interesting. The Spyder logo is corroded quite badly. It was not dunked, but probably got a bit of my sweat on it as I carved. I could really care less about this because some scotch bright pad ought to take it right off, but I though I would share and image anyway.
<a href="http://www.flickr.com/photos/ewerstruly/5562030062/" title="IMG_0941 by ewerstruly, on Flickr"><img src="http://farm6.static.flickr.com/5304/556 ... 5b9ce0.jpg" width="500" height="374" alt="IMG_0941" /></a>

Another image:

<a href="http://www.flickr.com/photos/ewerstruly/5562099716/" title="photo(3)-1 by ewerstruly, on Flickr"><img src="http://farm6.static.flickr.com/5309/556 ... 3a0e87.jpg" width="500" height="422" alt="photo(3)-1" /></a>

The Spyder was black before, now a crusty white and brown finish has replaced it. I scrubbed it with my finger and no change.

Big deal....It is a great knife!

[chuck_roxas45]

Oh I love my GB. Unfortunately since me and my wife sold our farm several months ago, I no longer have a lot of occasion to use a knife. I would have loved to put my GB through it's paces and pushed the steel somewhat.