M4 Mini Grip Quality question

mkjellgren · May 25, 2013

Charles Bronson said:
Don't think it's to identify blade steel. Compare the different "hole" pattern on the OP's knife and on one of mine...
I don't know. Should I disassemble some other M4 BMs and mini grips just because of my curiosity? I've never seen such holes on a BM blade and I got more than I can count right now.

Hmm...I guess I've got no idea then. I just know I have 2 knives with the holes, and both are limited editions, one in m4 and one in m390.

Edit: after inspecting both photos again I noticed that while the hole pattern might not exactly match, the number of holes is the same. Meaning the number of holes is the indicator, whatever that indicator might be for. My best guess is still that it designates a particular version of a model. For example, the standard blades would feature no holes, because they wouldn't need them being standard models, then each different variant or blade steel would feature a different number of holes. It would be interesting to see if other knives that are available in a variety of blade steels also feature these holes on the variant models.

The Mastiff · May 25, 2013

CPM M4 begins temper at a thousand degrees F. and goes up from there. Anneal is like 1600. Hardening is pretty high! It is a high speed steel. I'd be surprised if the steel is really affected. Probably just the coating which is likely applied at, and rated to lower temps. This is of course just a guess but I'm not worrying about it on mine.

Joe

Luis G. · May 25, 2013

The Mastiff said:
CPM M4 begins temper at a thousand degrees F. and goes up from there. Anneal is like 1600. Hardening is pretty high! It is a high speed steel. I'd be surprised if the steel is really affected. Probably just the coating which is likely applied at, and rated to lower temps. This is of course just a guess but I'm not worrying about it on mine.

Joe

This is where I am at with mine, probably the coating. Testing edge retention seems to do just fine. I sent it to benchmade just to make sure, also to check the hardness.

Charles Bronson · May 25, 2013

The Mastiff said:
CPM M4 begins temper at a thousand degrees F. and goes up from there. Anneal is like 1600. Hardening is pretty high! It is a high speed steel. I'd be surprised if the steel is really affected. Probably just the coating which is likely applied at, and rated to lower temps. This is of course just a guess but I'm not worrying about it on mine.

Joe

Neither am I worried. Looks like the coating got burnt during grinding/sharpening.

The holes are a mystery though. They are quite rough and irregular. Could be what mkjellgren pointed out, but I would imagine BM had the means to put a nicer marking on the blade.

Furthermore, the holes come in contact with the washers. Sebenza comes to mind. Maybe pockets to "store" grease or oil?
The holes are rough, however, and I could imagine them creating some friction, but my knife is extremely smooth, especially after applying a teflon-based, fluorinated grease.

The hole pattern just looks so messy, I can't think of a machine or process creating it on purpose.

@mkjellgren I am separated from my collection for the weekend but I will check all my limited edition BMs just to be sure.

The Mastiff · May 25, 2013

It will be interesting finding out what the holes are for, or from. It could be a few things but if it's on purpose the grease sounds most likely. One wouldn't think balance issues would be done to that extent as it doesn't move fast or far. Skimming excess grease off, or possibly holding it as you state. It has me curious too.

Joe

Luis G. · May 25, 2013

Just took in a Benchmade Griptilian in CPM-M4 (2013 Shot Show LE). No burnt tip at all under loupe. Hard to tell if it's actually burnt since it's black cerakote but would be easily distinguishable from the finish.
I don't see any differences in finish from the tip and rest of the spine, so I think I can say no burnt tip on this one.

It's possible it's just the coating. Benchmade should have received my other LE CPM-M4 Griptilian by now we'll see what they say in a week or two's times.

To be honest I am not worried in the least even if the temper is bad (which I doubt, Edge retention was excellent and putting a micro bevel while checking under magnification seemed normal).

Wanted to add:
What I love about Benchmade is they have NEVER shied away from a warranty claim from any of my concerns. I've brought them heavily modified knives, never once have I heard an excuse from them in fact I've received compliments once or twice, and even once a hand in fixing a small issue I my self caused during a mod.

Before I sent it in, I asked if it could be a problem replacing the blade if it turned out faulty explaining it was a LE: They mentioned it could prove difficult but they could work something.

Charles Bronson · May 25, 2013

Just told a friend who's an engineer about this issue. He's not into knives, so he's somewhat unbiased.
He works with CNC and first thing that came to his mind: maybe a code. However, after seeing the messy pattern he dismissed that idea.

Here is my final theory:

1. Burnt tip: Ceratoke finish is applied before grinding/sharpening. Didn't quite hold up to the heat generated during the process.

2. "Holes": Maybe BM is experimenting with "pockets" to hold the grease/oil like Chris Reeve does with their washers (maybe the CRK washer design is patented, so BM does it to the blade itself). The holes are all at the same spot (under the washers) and the spaces between the holes seem even, so it has to be on purpose.
Maybe they didn't realize they had a faulty/broken drill bit on their CNC machine before they were done with the series and didn't bother to start from beginning...

The "grease pockets theory", however, doesn't make sense considering BM's warranty policy not to disassemble the knives.

JNewell · May 25, 2013

For whatever it's worth, I have a couple of the gray Cerakote M4-bladed BM Forum knives and the tips do not show anything like what's shown in the pictures here. It's true that the blade is somewhat larger, so maybe the greater mass of the blade is a more effective heat sink.

loonybin · May 26, 2013

Charles Bronson said:
Just told a friend who's an engineer about this issue. He's not into knives, so he's somewhat unbiased.
He works with CNC and first thing that came to his mind: maybe a code. However, after seeing the messy pattern he dismissed that idea.

Does he work with plasma and laser cutters also? That's what Benchmade uses -- not a CNC with a drill bit. The blades are cut out of a sheet with a plasma or laser cutter.

Here is my final theory:

1. Burnt tip: Ceratoke finish is applied before grinding/sharpening. Didn't quite hold up to the heat generated during the process.

I had a burnt tip on a satin finish mini-Onslaught, so it has nothing to do with the Cerakote. It has everything to do with the heat generated during their hand-sharpening. Brownish discoloration apparently is only cosmetic, according to the note returned with the mini-Onslaught when I sent it in for warranty replacement of the blade. Now, bluish discoloration would mean the temper is affected and the blade should be replaced.

2. "Holes": Maybe BM is experimenting with "pockets" to hold the grease/oil like Chris Reeve does with their washers (maybe the CRK washer design is patented, so BM does it to the blade itself). The holes are all at the same spot (under the washers) and the spaces between the holes seem even, so it has to be on purpose.
Maybe they didn't realize they had a faulty/broken drill bit on their CNC machine before they were done with the series and didn't bother to start from beginning...

The "grease pockets theory", however, doesn't make sense considering BM's warranty policy not to disassemble the knives.

Then they've been "experimenting" for a couple of years. 154CM bladed Presidios have no extra hole in the blade. M4 Presidio made in 2011 on the other hand... 154CM blade Griptilian has no extra holes in the blade. M4 blade does... Does the D2, s30v and N680? If they do have holes, how many on each different steel? If someone was brave enough to disassemble a mini-Barrage and a Cabela's mini-Barrage with D2, I wonder if we would find a hole or two in the D2 blade.

My money is still on a designation of which steel. Satin finished D2, s30v, 154CM, and N680 all look pretty much the same. The hole will tell employees what steel it is before being lasermarked. Using a laser or plasma cutter would account for a hole or two not being perfectly cut through (little bit of slag left in it).

Charles Bronson · May 26, 2013

loonybin said:
Does he work with plasma and laser cutters also? That's what Benchmade uses -- not a CNC with a drill bit. The blades are cut out of a sheet with a plasma or laser cutter.

My money is still on a designation of which steel. Satin finished D2, s30v, 154CM, and N680 all look pretty much the same. The hole will tell employees what steel it is before being lasermarked. Using a laser or plasma cutter would account for a hole or two not being perfectly cut through (little bit of slag left in it).

No, he does not work with plasma and laser cutters, so we forgot to consider that.

I think you solved the mystery. I can (only) imagine that a laser or plasma cutter would leave such a "messy" pattern.

I am brave enough, so now I have to check other LE BMs to see if they got the holes and if so, how many...

P_Meticulous · May 26, 2013

You guys could always contact Benchmade regarding the holes - just sayinnnn

(Granted, not on Sunday of course)

I've never had a burnt tip, I would send that back for lack of QC

loonybin · May 27, 2013

P_Meticulous said:
You guys could always contact Benchmade regarding the holes - just sayinnnn (Granted, not on Sunday of course)

Now where's the fun in that?

Charles Bronson · May 27, 2013

loonybin said:
Then they've been "experimenting" for a couple of years. 154CM bladed Presidios have no extra hole in the blade. M4 Presidio made in 2011 on the other hand... 154CM blade Griptilian has no extra holes in the blade. M4 blade does... Does the D2, s30v and N680? If they do have holes, how many on each different steel? If someone was brave enough to disassemble a mini-Barrage and a Cabela's mini-Barrage with D2, I wonder if we would find a hole or two in the D2 blade.

My money is still on a designation of which steel. Satin finished D2, s30v, 154CM, and N680 all look pretty much the same. The hole will tell employees what steel it is before being lasermarked. Using a laser or plasma cutter would account for a hole or two not being perfectly cut through (little bit of slag left in it).

BM 710-1 KW exclusive, M390 steel... 4 relatively clean holes!