CRK fixed blade question

[nyefmaker]

CRK uses A2 which is basically a tool steel that will not allow "flex". The schrade was made with a lesser steel that will allow more "flex". Did you see the noss test with the kukri ? He actually had to bend the kukri in half in the vise and it still did not break. The steel was very cheap. If you did that with a high end kukri ( cold steels better models ) it would surely break as the higher end steels will not allow to much "flex". The Only High End steel I have ever seen that will allow such flex is INFINI steel Busse uses and some of the other steels their brother companies use. But in my experience, uncoated busse steel rusts, so what your achievin in one area, your givig up in another. Upon seeing the videos, that is what I came away with. A cheap steel will not hold an edge, but you can hit the edge on a file for instance and the edge will just ding or roll up, it will not chip. While a high end steel will chip because its much harder and of better quality. After the tests, I even posted for noss to use a non serrated version to prove me and others wrong, but they were never done. I still believe my reasoning is correct. This test in no way effected my buying one-piece knives. My only reasoning for wanting CRK to do a green beret and pacific in non serrated versions is that I just dont like serrations on knives as they do not help me in any way when I am using them in the field.

 

[dl351]

I second what nyefmaker says. I actually emailed Taylor Cutlery a while back (the parent brand of Schrade) and found out that their one piece is on average 3 points softer on the Rockwell C scale than the Reeve. That, along with the fact that it's made of 1075 steel means it is more of a spring temper than Reeve's knives which means it will flex more, but at the cost of edge holding. Hope this helps.

 

[nyefmaker]

I second what nyefmaker says. I actually emailed Taylor Cutlery a while back (the parent brand of Schrade) and found out that their one piece is on average 3 points softer on the Rockwell C scale than the Reeve. That, along with the fact that it's made of 1075 steel means it is more of a spring temper than Reeve's knives which means it will flex more, but at the cost of edge holding. Hope this helps.

Very Well Said

 

[STAGE 2]

CRK uses A2 which is basically a tool steel that will not allow "flex". The schrade was made with a lesser steel that will allow more "flex".

More questions.

Does flex/bending really come into play when metal is being struck. I would understand if it snapped while being used as a pry bar, but being driven into wood, even with metal doesn't seem to apply to those kinds of forces.

Second, if this is the case, then shouldn't the RAT which is hardened to 57 and thinner overall have experienced a similar failure?

 

[MORIMOTOM]

More questions.

Does flex/bending really come into play when metal is being struck. I would understand if it snapped while being used as a pry bar, but being driven into wood, even with metal doesn't seem to apply to those kinds of forces.

Second, if this is the case, then shouldn't the RAT which is hardened to 57 and thinner overall have experienced a similar failure?

i think i understand your question as this: a more "bendy" knife would not affect its resistance to breakage.

if so, i would suggest it most certainly does. a knife which allows for more flexing is likely more impact resistant, or less brittle, allowing it to absorb more shock. rockwell hardness is only one measurement of a steels capabilities.

 

[nyefmaker]

More questions.

Does flex/bending really come into play when metal is being struck. I would understand if it snapped while being used as a pry bar, but being driven into wood, even with metal doesn't seem to apply to those kinds of forces.

Second, if this is the case, then shouldn't the RAT which is hardened to 57 and thinner overall have experienced a similar failure?

Is the RAT made from A2 ? I do not own any RAT knives to see. Every steel has different properties and heating 2 different steels to the same Rockwell hardness does not mean they will perform the same. S30V might be very brittle at say 62 RC, while it performs exceptionally at 58 RC, while another steel say 1095 is too soft at 57 RC, but performs better at 62 RC. This just an example. A2 is a tool steel that is made for hardness and not flexibility. Take a file and put it in a vise. Its more likely to snap in half than bend because it was designed to cut metals nearly as hard as itself. I dont know if there would have been a better steel for the OPR, but if its good enough for Chris, its easily good enough for me. He forgot more about knives than I will ever know.

 

[missin_hobo]

I dont know if there would have been a better steel for the OPR, but if its good enough for Chris, its easily good enough for me. He forgot more about knives than I will ever know.

Exactly. People forget that (publicly at least) this is the first and probably only instance in their entire 30-odd year history that a one-piece knife has been broken.
What's more, it only broke because something was done to it that you would never, ever, ever, even in the most dire circumstance, attempt with your own knife.
People have been out with these knives, in wildernesses and battlefields, beating on them with sticks and even rocks, for the last few decades now. That isn't suddenly invalidated by a guy with a hammer.

 

[STAGE 2]

Is the RAT made from A2 ? I do not own any RAT knives to see. Every steel has different properties and heating 2 different steels to the same Rockwell hardness does not mean they will perform the same. S30V might be very brittle at say 62 RC, while it performs exceptionally at 58 RC, while another steel say 1095 is too soft at 57 RC, but performs better at 62 RC.

The Rat is 1095 hardened to 57 RC. I understand and pretty much agree with everything you've said, its just the one thing that I can't get over is that the project is a big hunk of steel. Yes its not the most flexible steel and yes it has serrations, but its still a 1/4" slab of A2 and we are still hammering into wood.

Before this test was done, most people here including myself believed that the one piece would be one of the top performers. The fact that so many people here were surprised indicates to me that this knife, despite the serrations and inflexibility, was expected to perform far better.
So I guess my question is shouldn't the sheer thickness of the knife and the medium (wood) mitigate the flexibility issues. A2 might not be spring steel, but at 55-57 its not exactly glass either. If 1095 @ 57 RC can take a cinderblock shouldnt this one piece handle a sledge into wood?

If the answer is no, then could someone explain to me what is the purpose of a knife this thick in this steel? Making it thinner would dramatically increase the cutting ability without making a practical difference in durability.

 

[dl351]

Stage2, the best answer I can give you is that it's 1/4" thick simply to strengthen the knives. Now, let me explain why I say this. I have several Scrap Yard knives and a couple Swamp Rat knives. Most of their 7" blades are very wide blades. For example, my Scrap Yard SOD is 1 3/4" wide. That knife makes my SOG Seal 2000 seem small. Comparably, from scaling and checking dimensions, I'd estimate that the Project 1 blade is 1 1/8" to 1 1/4" wide. Since the Project 1 has a hollow grind to improve slicing (which makes for more thin portions of the blade compared to flat grinds), I'm guess that the 1/4" spine thickness is simply to add strength to a knife that doesn't have a huge blade (compared to some of the "indestructible" knives out there). Also, weight for chopping might be an added benefit due to the thickness. The way I see it, if the knives preform flawlessly batoning through wood with wood, I don't have any problems.

As an aside, I also agree with missin hobo. In the past 10 to 15 years that I've known of Chris Reeve one piece knives' existence, the only broken one I have ever seen anywhere is on a knife destruction website.

 

[LostSoul]

I'm new to the board so don't roast me to bad, but I just have to put my poker into the fire. I don't know the science behind the metals but do know that a knife, regardless of what brand, steel, size, etc., is simply a tool. A tool, if used improperly may not hold up to the abuse. You don't use a circular saw to hammer nails do you? I'm not a rich man, as a matter of fact I am a lowly land surveyor who spends a lot of time in the woods not only working, but hiking and camping, and I have no problems trusting my CRK. If I a need to chop something, I will use a machete or hatchet. What's that you say?, what if you don't have a machete or hatchet with you? Well if you don't have one of those 2 tools with you, you surely won't have a hammer either.

Now I don't know about you guys, but for me I would rather go out with the proper tools to start with than risk damaging something, most importantly myself. The term "nearly indestructible" is subjective, and without putting words into anyone's mouth, I highly doubt that if CR made that comment, he never envisioned someone beating on a knife with a 2lb sledge hammer.

 

[Buffalohump]

Why don't you just buy one and test it yourself? I think you'll find that once you've invested $200 + you'll treat the knife with due care and consideration and in all likelihood it will outlast you.

and Dead.

Didn't mean to create such a commotion and debate (again apparently). I appreciate all the input, but was specifically just asking if they ever mentioned anything about tweaking their heat treatment processes and such. It seems they have not... which is ok, but because of that I will most likely stick with other manufacturers for fixed blades. Thanks everyone-

 

[hbui]

They are great knives. I don't get to use my 4 OPR often but when I do, I love them. To me comments from users carry more weight than tests which are ridiculous.

 

[dl351]

They are great knives. I don't get to use my 4 OPR often but when I do, I love them. To me comments from users carry more weight than tests which are ridiculous.

That's the same mindset I have. I questioned about the skinner in another thread and it sounds like nyefmaker has put it through the paces without a problem. Real experience holds more weight than intentional destruction.

As a side note, does anyone here think that some knife nuts are more crazy about indestructible knives these days than they used to be? It seems to me that the knife industry has moved more towards "hey! look what our knives can be put through!" I'm not saying that tough knives are bad, but touting toughness over most other aspects of a knife seems to draw away from a knife's actual purpose.

 

[SVC]

I'm not an expert on metals but it occurs to me that the failure may be due to the shape of the knife and how it reacts to the heat treatment. Because the blade is long and thin and therefore has much more surface area than the handle, is it possible that the handle is cooling more slowly than the blade and this difference is causing a weakness near the junction?

That would mean that the problem is a flaw inherent in the one piece design when made with these metals.

A comment about both metals that cracked not allowing for differential cooling made me think of this possibility.

 

[Jack Shen]

I've owned a shadow (forgot number, it has a 7 inch blade, and was discontinued and replaced with the project knives) for 14 years. Never had a problem, I use it as a knife, and not an axe, chisel, or prybar. I think this thing will be around long after I'm gone

The coating has never come off, and after this long, it still has the original blade shape.

If you take care of it you won't have a problem. It however WILL NOT last if you use it as a prybar or forcefully whack it on something like concrete flat side first.

If you think about it, a Japanese sword, which is extremely tough and meant to sever limbs, having a hardness of about 60 or above wouldn't be able to take that kind of abuse either.

 

[STAGE 2]

Because the blade is long and thin and therefore has much more surface area than the handle, is it possible that the handle is cooling more slowly than the blade and this difference is causing a weakness near the junction?

There isn't anything thin about a 1/4" thick blade.

If you take care of it you won't have a problem. It however WILL NOT last if you use it as a prybar or forcefully whack it on something like concrete flat side first.

I've heard this from just about everyone who has come to the defense of CRK. The problem is that this just isn't realistic when marketing a knife towards soldiers. Anyone who's spend at time around the military knows that its almost a certianty that equipment is going to be used for something other than its intended purpose. This knife is no different.

If you think about it, a Japanese sword, which is extremely tough and meant to sever limbs, having a hardness of about 60 or above wouldn't be able to take that kind of abuse either.

On the contrary, a sword like that would be able to easily take this abuse because, if don't traditionally, only the edge is extremely hard. The bulk of the blade is much much softer to be able to withstand the abuse of metal on metal contact.

 

[SVC]

There isn't anything thin about a 1/4" thick blade.



1/4" is thin relative to a handle that is more than an inch in diameter. And, most critically, the volume to surface area ratio of the handle is much larger than that of the blade which, again, could mean that despite being heated and cooled in the same conditions, there is a significant difference in the rate of cooling of the two locations.

It's all conjecture - I was hoping someone with a metallurgy background might offer their opinion!

 

[Buffalohump]

Japanese swords are laminated of two different steels so that the edge is harder to allow it to take a razor's edge but the flats and spine are flexible so that it will not snap when it receives a major shock from impact (ie, hitting bone).

If you think about it, a Japanese sword, which is extremely tough and meant to sever limbs, having a hardness of about 60 or above wouldn't be able to take that kind of abuse either.

 

[coldsilence55]

I really didn't want to post on this thread again as I (for the most part) got the answers I was looking for. But I just can't resist... everyone saying 'oh well just dont hit it with a hammer...' fair enough, we get it... we will not be hitting our knives with hammers. If all knives snapped in half when hit by hammers, this whole thing would have ever been an issue. This is, however, not the case. There are many many other knives that take 10 times more abuse and are made of the same steels. An example of this (using only examples tested on knifetests) is the Strider BT. It is made of S30V just like the CRK GB. This knife ran right thru the hammer test... and then onto the cinder block test etc etc. And then onto batoning thru a metal chair (with large hammer again) where if finally broke after much, much, much more abuse than the CRK. At this point... a quick reminder... this is the same steel we are talking about. And to try justifying this by saying the CRK is simply a higher rockwell... well, I have not heard of anyone complaining that Striders can't hold an edge at all... so wheres the advantage (other than being more difficult to sharpen)?

To everyone saying that they have not heard of one breaking other than in these tests... that may be true, but then again... how many people that own CRK knives are members on blade forums or even post on the internet at all. I am confident in saying that even if a lot were broken, we would probably not know about them. If CRK won't directly address the knifetest issue, then they obviously won't be making it public knowledge when a knife comes back broken. And because its not a no questions asked guarantee like other makers have, if one is broken while being 'abused' it probably won't even get sent back at all.

No matter what side of the fence you fall on, the fact is there is a problem with the heat treatment of the steel (compared to that of other makers). 1095 is not a super steel. It is a good all purpose steel that is made all the much better by makers like Rat because of their heat treatment. My original post was asking if CRK had fixed their heat treatment, but if they have never mentioned it then we must assume its the same.

As a suggestion, why not just do a deferential heat treatment. Softer spine, harder edge. Charge a little bit more, have a tougher product with the same edge retention.

 

[dl351]

Why do you insist that it's the heat treat? It's been mentioned before that both Reeve knives broke in the middle of a serration. That signals that the serrations could be acting as stress risers. As for people posting on BF, Horn Dog posted somewhere on here using his Green Beret (I think that was the model). He batoned (with wood) and even threw his knife without any problems. Also, if these knives are so fragile and break so easily, I don't think Chris Reeve knives would be as popular as they are, regardless of the internet or knife forums. Also, unless the response posted from Reeve Knives earlier in this thread was a lie, somewhere around a dozen knives have been broken over 25+ years of them making fixed blade knives.