Update on broken knife...

Ben :

In this article a Companion model and a MST were put through some torture testing.
Click to expand...

Are there two models of this blade - is the MST II that Chiro had a MST with a swedge?

I believe you should have gotten a new blade and the old one should have been used for research.
Click to expand...

The tip snapping in the manner that Chiro described does not indicate the level of performance I would want in a blade. I would have asked Greco if that was to be expected. If he said no I would have asked for a replacement. If he said yes I would have wrote off the blade. Experience is not always free.

-Cliff
 
Well, guys, I don't know what to tell you. I guess I don't feel overly entitled to a new knife because I'm not the original owner. Also, because I don't know exactly what sort of things the knife was put through by the original owner, then I can't really say if this stress that occurred through my use was the straw that broke the camel's back or what. If I was the original owner and the knife had never had point stress and it had suffered the same demise, I probably would have gone for the replacement over the repair. In this case I am uncomfortable doing that because in my mind I could potentially be making the Grecos pay for something that was unreasonable. As I said, I am happy with the repair option, and I am confident that the problem will be taken care of. If it is a bad piece of steel, then the defect is essentially gone. If it's a bad heat-treat, then the problem may occur again. If it does, then there is no doubt in my mind that John and Sherry would be more than happy to look into the problem and take care of it another way. There is always the possibility that the knife had a lot of heavy use before I owned it, so I can't say with certainty that the tip wasn't stressed enough to break with light pressure. Also, as much as I hate to say it, I must admit that my recollection may not be 100% accurate. Not that I am deliberately misleading anyone, but the test was performed with every expectation that the knife would pass with flying colors. As a result, this means that my recollection of the events are retrospective, so I wasn't measuring and quantifying things as I went. I think my recollection is accurate, but if I'm off ten or fifteen degrees, then that could change our impression of the stresses dramatically. The bottom line is that John and Sherry had every right to tell me to f-off, and instead they listened intently, talked the matter over, treated me very, very nicely, and offered to repair the knife at a cost I was agreeable to. This made me happy enough to buy another knife from them, and obviously they were happy because they now have a loyal customer as well as input for possible changes to future knife design. Thanks for all your input, guys!

------------------
My Knife & Sheath Pages:
http://www.geocities.com/CollegePark/Lab/1298/frames.html
Palmer College of Chiropractic
Sheath Makers Referral Directory
agocs_s@dd.palmer.edu
Madpoet (Mel Sorg, Jr.) Tribute page:
http://www.geocities.com/CollegePark/Lab/1298/madpoet/main.html
 
Great post Chiro, thank-you. The reaction to your broken knife story sure was interesting. I learned something. I think.
smile.gif


Paracelsus, observing that fires sometimes start for no reason, and Do sometimes go out all by themselves
 
Chiro :

I don't feel overly entitled to a new knife because I'm not the original owner.
Click to expand...

Is this a part of Greco's actual warrenty?

I don't know exactly what sort of things the knife was put through by the original owner
Click to expand...

That is a reasonable point. If someone took the blade and bent it past the plastic limit at that point over and over it could easily lead to the problem you describe. Or he could have effected the temper or subjected it to really heavy impacts.

However, it would be difficult to do this though without it being obvious - and do you really think the seller is the kind of person to do this and not tell you about it? Can't you just ask the previous owner about the kind of use it recieved?

-Cliff
 
Sounds reasonable to me Chiro.A piece of steel can be flexed only x number of times before it gives.If you just happened to get it with X minus 1 flexes I guess that is life.Cliff in the article the MST and Companion both had long swedges in fact the blades look very similar.The differences were in the guard and handle.I think both knives are beautiful and seem like very practical using knife designs.The article says that John heat treats and rockwell tests his blades.I'm not saying Chiro was "owed" a new blade by John.It's just that when I have a piece of work that fails I can usually learn a lot by running more tests on it.I would have liked to see John take the tip and blade with him to check the rockwell just so the possiblity of the steel
or heat being bad was eliminated.The reality is :as long as Chiro is happy with the outcome that is the important thing.I believe Greco's knives are tough.I dont think what happened to Chiro's blade is normal.I also in no way am I saying that this is in any way John Grecos fault.I just wanted to make that clear.I want to buy some knives from the guy and I'm sure I will sometime just not at this time.
troy
 
Ben :

A piece of steel can be flexed only x number of times before it gives.
Click to expand...

Fatigue lives for high quality steels are very high and in general you need to exceed 35 to 60 % of the tensile strength to even cause fatigue to happen. Unless you exceed the plastic limit it is very unlikely that you will see failure due to fatigue in your lifetime. For example low cycle fatigue limits (high stress use) are between 10 000 and 100 000 cycles.

-Cliff
 
Thanks for the correction, Cliff, on that steel fatigue thing. Aluminum has a definite fatigue life, but most steels have an almost infinite fatigue life as long as the loads are reasonable. To answer your questions, Cliff:

1) I have no idea what John's written warranty is as I have never seen one. I didn't receive one with my new knife, so there is a possibility one doesn't even exist! He's as nice a guy as can be, though, and Sherry is even more of a pleasure to deal with! She's so nice I think she would've sat me down and made me an apple pie if she would've been in a kitchen instead of a knife show!
biggrin.gif


2) The original user bought the knife expressly for a camping trip, and it was definitely used. he said he did everything with it, from chopping to cutting to splitting wood with it. FWIW, the spine did not have damage to it that I could see, so if it was used as a wood splitter with something pounding on the spine for power, then it wore the abuse very, very well. Like I said, I was 100% satisifed with the outcome of this situation, and I have a feeling we're beating a dead horse by taking this discussion further since John isn't available for input...

------------------
My Knife & Sheath Pages:
http://www.geocities.com/CollegePark/Lab/1298/frames.html
Palmer College of Chiropractic
Sheath Makers Referral Directory
agocs_s@dd.palmer.edu
Madpoet (Mel Sorg, Jr.) Tribute page:
http://www.geocities.com/CollegePark/Lab/1298/madpoet/main.html
 
Chiro :

most steels have an almost infinite fatigue life as long as the loads are reasonable.
Click to expand...

Yes, low-medium stress loads have cycle limits in the 1 to 10 million range. It would take you quite a while to do that even if you did nothing else.

I have a feeling we're beating a dead horse by taking this discussion
Click to expand...

Chiro, while the issue is resolved for you there are other people interested in his blades and you have influenced their perspective with this thread. Personally for example I am still not clear on if Greco thought was you saw was the expected result. However the issue is not as critical as it was a couple of days ago because of the article Ben cited.

-Cliff
 
Ummm, am I missing something in the discussion of the re-grinding repair here, and the original problem possibly being a bad heat treat? I mean, if the blade is re-ground, won't this ruin the treat, resulting in a new treatment being required? Or am I out to lunch here?

------------------
iktomi
 
Grinding only ruins the heat-treat if it's done by an idiot who overheats the blade.

-Cougar :{)
 
You must log in or register to reply here.
Back
Top