Is this normal for M4?

[btb27823]

Recently received my Gayle Bradley. Solid feel, great fit and finish. Reprofiled the edge to 35 deg. included. Hair popping sharp. My normal edge for this type of knife.

Cut up about a dozen corrugated boxes (medium size) and found the edge had deteriorated to the point of no longer shaving or even slicing paper well. This is disappointing as my knives in 1095, 5160, 52100, D2, S30V, 440C, VG10 all perform better in edge retention. I am surprised to say the least.

Anyone else have a similar experience with CPM M4?

[Stugots-II]

There was another formite on here like a month ago saying the same thing about his Gayle. He pretty much stated the same thing as you about getting it sharp and it would lose its edge right away. Do you know when yours was made? There was talk/speculation about maybe it being during the date, nothing confirmed though. I will see if I can find the post.

[Stugots-II]

http://www.spyderco.com/forums/showthre ... le+bradley

Found it, check it out for starters

[Evil D]

Are you absolutely sure you didn't have a tiny burr or something that folded over after a bit of use?

[btb27823]

Thanks for the link. Sounds similar to what I am experiencing. Will see if I can find the date code. Know where it is?

[Stugots-II]

It depends if you have the box that the knife came in? On the outside of the box there are two letters that correspond to a production date.

The first letter is the month and then second letter is the year so C/J would be March. 2010.

[btb27823]

Have finished with 0.1 micron diamond grit film, 10K Sigma Power stone, 8K Kitayama and Spyderco UF ceramic. All produce about the same results in terms of edge retention. No evidence of a burr with any finishing material as viewed with a high quality 30 power loop.

[btb27823]

It depends if you have the box that the knife came in? On the outside of the box there are two letters that correspond to a production date.

The first letter is the month and then second letter is the year so C/J would be March. 2010.

The date code is KJ (Nov. 2010)

[Stugots-II]

Yeah I might try PM-ing Crimson to tell him your issues and see what came of his. If I recall correctly he was going to send them into Spyderco. He might have a some helpful info for you.

[Stugots-II]

The date code is KJ (Nov. 2010)

Crimson's was JJ so just the month before but who knows where the cut off point was. Your two might be close enough that if there was a bad hardening or something with a few that your two could have been together.

He never followed up in his thread as to the action Spyderco took once he sent them in so he may now be able to help you some more. So like I said you could try PM-ing him. Otherwise give Spyderco a holler about your dilemma. They are always super nice and helpful...that is if you haven't found that out for yourself yet.

[btb27823]

Crimson's was JJ so just the month before but who knows where the cut off point was. Your two might be close enough that if there was a bad hardening or something with a few that your two could have been together.

He never followed up in his thread as to the action Spyderco took once he sent them in so he may now be able to help you some more. So like I said you could try PM-ing him. Otherwise give Spyderco a holler about your dilemma. They are always super nice and helpful...that is if you haven't found that out for yourself yet.

Thanks, will do both. Will follow up next week when I talk to CS.

[Blerv]

Vg10 should be a nice baseline. Still m4 should be outperforming it for that task even heat treated lower than the early runs.

[Tsujigiri]

Not normal at all. CPM-M4 should blow the other steels out of the water. Mine is also KJ, and it had no noticeable dulling after cutting up this cardboard:

It sounds like yours is defective; you should probably send it in.

[The Deacon]

Keep it mind that Spyderco has never specified whether their date codes represent date of manufacture, or date of packaging (in Golden, regardless of where the knife was made). So there's at least some possibility that knives with dates in consecutive months were produced at the same time. Even if that's not the case, one cannot reasonably assume that either all the knives with a given date code have blades from the same HT batch or that all blades from a given HT batch wound up being used in a single production run. So, even if only a small percentage of blades in one particular HT batch were "soft", those blades could, conceivably, be spread across two consecutive date codes.

[btb27823]

Crimson's was JJ so just the month before but who knows where the cut off point was. Your two might be close enough that if there was a bad hardening or something with a few that your two could have been together.

He never followed up in his thread as to the action Spyderco took once he sent them in so he may now be able to help you some more. So like I said you could try PM-ing him. Otherwise give Spyderco a holler about your dilemma. They are always super nice and helpful...that is if you haven't found that out for yourself yet.

Spoke with Spyderco CS on Tue and shipped the knife out on Tue. afternoon. They said they would test HRC at three places just behind the edge. Would leave permanent conical indentations (I knew that but still...ouch!) Asked it they had an edge retention test and the answer was equivocal. Would like them to get a hardness number AND do a standard edge retention test. Will see if that happens, would be nice.

BTW, PM'ed CrimsonTide and no response yet. May not be on line that often?

Will get back when I get results from CS

[btb27823]

Spoke with Spyderco CS on Tue and shipped the knife out on Tue. afternoon. They said they would test HRC at three places just behind the edge. Would leave permanent conical indentations (I knew that but still...ouch!) Asked it they had an edge retention test and the answer was equivocal. Would like them to get a hardness number AND do a standard edge retention test. Will see if that happens, would be nice.

BTW, PM'ed CrimsonTide and no response yet. May not be on line that often?

Will get back when I get results from CS

Got results! Rockwell of my knife and another new one they tested with the same or nearly the same date code tested 64 :) My knife passed the CATRA test, but no more info. than 'passed.'

They said the edge as received had minor rounding...probably from me over stropping. Had tried a very small microbevel and stropped with 0.1 micron diamond paste on firm leather. That could have been the cause of the 'rounding', perhaps too much of a good thing. But they said it was shaving sharp as received.

Not finding anything wrong, I expected my knife to be received with the 5 hardness indents in it (they tested 5 places, not just 3 along the edge). But Spyderco went the extra mile plus and are sending me a new knife! Wow, impressed to say the least.

So, I am going to leave the edge unaltered and use it as my EDC cutting plastic wrap, rope, corrugated, etc. Have been using my little BM D2 707 Sequel as my EDC while the GB was being tested, so I am going to dress the edge and use the two side by side to see how they compare. M4 should beat D2 every time, so it will be interesting to see.

So, at this time, I have no real explanation of why the edge of the GB would degrade so quickly. Poor sharpening of M4? Anything is possible. It is my first experience with M4 although not with higher end steels in general. I checked the edge with a high quality 30 power loop, but I am going to upgrade my optics and get a scope so I can see and photograph what is happening...the only way to really tell.

So, for anyone following this thread, wondering if the knife/steel was up to speed, Spyderco testing says it is! I have no reason to doubt, so at this point, until more experience proves otherwise, I am going to assume it is a problem at my end. Hopefully I can find out what and fix it.

[chuck_roxas45]

I admire your "immediate action" attitude. So you got in touch with Spyderco CS and got a resolution pretty quickly instead of just talking about the issues here. Bravo!

[unit]

I think the answer may be what many others have said before: cardboard is a mystery material. Some cardboards are paper and glue, while others contain all sorts of recycled garbage. I have seen metal fines and other abrasives in cardboard. I have also seen a mirror edge stropped on cardboard...the results demonstrated clearly the abrasive properties of the material...try it on several different samples of cardboard and you will see.

[bob7]

Almost same experience w/ my Bradley. My battery acid like sweat corroded the edge a little bit after extensive inside the waistband carry. I re-sharpened the knife first w/ a medium diamond ez lap rod and then finished w/ a medium and then fine DMT diamond embedded sharpener. The edge literally broke off after some use in a supply room cutting up boxes. I was able to break off little chunks of the burr w/ my thumb. It was a very distinct burr that I hadn't noticed until it bent and broke. I went back and re-sharpened again like above, and the knife was fine and has been fine ever since. I guess I wasn't used to such a big burr being produced; it was lined up perfect like an edge but wasn't the edge. :o

[JNewell]

Excellent report and results. Thanks!

Got results! Rockwell of my knife and another new one they tested with the same or nearly the same date code tested 64 :) My knife passed the CATRA test, but no more info. than 'passed.'

They said the edge as received had minor rounding...probably from me over stropping. Had tried a very small microbevel and stropped with 0.1 micron diamond paste on firm leather. That could have been the cause of the 'rounding', perhaps too much of a good thing. But they said it was shaving sharp as received.

Not finding anything wrong, I expected my knife to be received with the 5 hardness indents in it (they tested 5 places, not just 3 along the edge). But Spyderco went the extra mile plus and are sending me a new knife! Wow, impressed to say the least.

So, I am going to leave the edge unaltered and use it as my EDC cutting plastic wrap, rope, corrugated, etc. Have been using my little BM D2 707 Sequel as my EDC while the GB was being tested, so I am going to dress the edge and use the two side by side to see how they compare. M4 should beat D2 every time, so it will be interesting to see.

So, at this time, I have no real explanation of why the edge of the GB would degrade so quickly. Poor sharpening of M4? Anything is possible. It is my first experience with M4 although not with higher end steels in general. I checked the edge with a high quality 30 power loop, but I am going to upgrade my optics and get a scope so I can see and photograph what is happening...the only way to really tell.

So, for anyone following this thread, wondering if the knife/steel was up to speed, Spyderco testing says it is! I have no reason to doubt, so at this point, until more experience proves otherwise, I am going to assume it is a problem at my end. Hopefully I can find out what and fix it.