Opinel Blade Failure

[Ebbtide]

Vivi, I admire your tenacity.
Others would have quit at the first inkling of deformation and impending ruin.
You kept going!
Bully!

That's it.
No Opinels for me.

 

[Cliff Stamp]

You sir are an idiot.

Good to see that the principles upon which Mike Turber founded Bladeforums are still active - no personal attacks.

There are Mora's made out of stainless steel with thinner blades than an Opinel which are intended to handle light chopping.

-Cliff

 

[canranger]

There are Mora's made out of stainless steel with thinner blades than an Opinel which are intended to handle light chopping.

-Cliff

Which models are you refering to????

Abe

 

[DaveH]

Have you guys ever thought that possibly the reason opinels are so inexpensive is the QA is rather loose?

It also seems risky to me, chopping, (or batoning for that matter) with an inexpensive knife, and a lightly built one at that.

if the knife is capable of doing it and I want to do it, by all means I'll do it

so, it sounds like the knife was not capable of what you where doing.

 

[Vivi]

Normally they are. This behaviour is an exception compared to my previous experience.

I think the picture showing the indentation from the ring lock clearly shows and improperly heat-treated blade, as the spine whack was by no means forceful. A point I think has gone rather undetected in this thread as a whole.

 

[Cliff Stamp]

Which models are you refering to?

There are many stainless moras 0.075" thick, the 4" opinels are about 20% thicker. The #749 for example is stainless steel with an eight inch blade. It is therefore made from thinner stock than an 4" opinel and is much longer and heavier so the chopping impacts are much higher. It handles chopping perfectly fine once you remove the initial hollow ground edge which is common on those knives.

I think the picture showing the indentation from the ring lock clearly shows and improperly heat-treated blade, as the spine whack was by no means forceful.

Even if the spine whack was forceful the blade should not be damaged. The locking ring should impact the wood and in extreme cases both it and the wooden handle will get damaged but the blade should be uneffected.

A point I think has gone rather undetected in this thread as a whole.

Facts and logic are not a strong point of trolls. They can also eat just about anything so the best course of action is to not feed them anything unless of course you enjoy their presence.

-Cliff

 

[Dog of War]

Vivi - can you give us an idea how thick the metal is where the edge chipped? Opinal geometry varies quite a bit .... also had you thinned it out?

I have an Opinel that's never been used hard and has some indentation on the blade from the lock ring. This particular knife came from the factory with a bit less blade width than usual so the lock ring engages practically at the edge. Yours however looks like a more serious problem. Honestly though, I'm not too surprised, since Opinels like most French cutlery tend to run on the soft side, so I can see how in the finishing and sharpening stages a blade with a bad heat treat could slip through unnoticed.

 

[db]

I don't think the cold would have anything at all to do with it. Probably swinging at angled cuts is what did it in combined with you thinning the blade. I've never had or held a #12 but I'd think the longer the knife the greater the force you can produce. Most Opinels are pretty thin to begin with how much did you thin it out? If real thin that could explain the locking ring denting the edge also. Try useing a small file on this Op and another one and see if you can feel a difference in how much the file scratches the blade. I'd do the lock ring too just for the heck of it.

 

[rebeltf]

I'm going to go with DWM on this one , maybe people in different parts of the world use different tools , who knows..... In my extended family there are a lot of hunters , we fish we hunt he kill we clean and not one of us has ever used a flippin' axe/hatchet to skin game , man do I want to roll my eyes on this but i'll keep it nice
I dont know what some folks on here are trying to prove , what - that you can do every chore you ever could do with one single blade ? Yea I know in the old days folks did not have multiple knives for different chores , my Granpa is great example , he had a well used Slipjoint , a large KaBar kitchen knife and a big axe, all three of which were used for different chores at camp or home.
Until I came here I never once heard of the term "batoning" unless a girl wearing a cheerleader outfit was nearby , batoning may be the acceptable practice in some parts of the world but I will stick to my axe or better yet, pruning shears for kindling wood ( why in the world would you baton when you can prune ).
There was another recent thread about batoning with an Opinel and while I respect other's rights to post a thread , I thought it was pretty silly to even consider such a task with a blade not meant for that task... An Opinel has a thin , fine blade far better suited for garden work or gutting fish , light carving or opening envelopes (my opinel performed these well) than to use it to build yourself a log cabin.

Look for a second at the blade and tip on your Opinel , if it is like mine both are very thin and fine , perfect for many (but not all) chores.

Anyways , Vivi I am glad you are learning this with more cost effectvie knives , this way it will much easier on your pocketbook every time you have to replace one....

 

[o1Alex]

I've never had a bad one, but i dont think they are good for chooping either!
I have a no 12 and i cut stuff with it....i saw a thread on battoning with an opinel and it sead to work ok....I guess you got the one bad in a million....

 

[shecky]

Tis a mystery. I've batoned with a much lesser 0.50" Opinel paring knife with no blade damage at all. And I baton the hell out of a cheap 12" Tramontina machete with 0.78" thick blade and it doesn't even seem to lose it's edge.

I have had a minor failure while chopping with an inexpensive folding knife. I used a Chinese Rough Rider, a large slipjoint Bulldog pattern "Deerslayer" model, to chop through a well seasoned pine 2x4, to have the backspring begin to deform. A perfectly reasonable failure. The knife is still quite usable, but the backspring is no longer flush along the spine and the blade hasn't the snap it had prior. Incidentally, the ss blade showed no damage whatsoever.

I'd expect the lock/pivot area on an Opinel to fail way before the blade when swinging/chopping. I'm with Cliff, that pic of the blade damage along the lockring area is telling.

I don't understand the controversy over Vivi's testing. I think the problem isn't that the blade failed, but rather the way it failed.

I find this test valuable. Seems to me a blade that fails in such a fashion against wood and it's own lockring would likely have very poor edge retention under "normal" usage. Perhaps they should make blades out of lockrings and lockrings out of blades? It would be interesting if we could get someone from Opinel to opine on this strange behavior.

 

[canranger]

Normally they are. This behaviour is an exception compared to my previous experience.

I think the picture showing the indentation from the ring lock clearly shows and improperly heat-treated blade, as the spine whack was by no means forceful. A point I think has gone rather undetected in this thread as a whole.

Possibly or the fact that the blade is the largest one they could me that the stress placed on the area hade a greater effect.

Example try standing on a 2 x4 with it suspended between to blocks at 8 feet watch it bow then withthe sanme 2 x 4 place the blocks 3 feet apart and stand onit it won't bow.

Just a thought

Abe

 

[canranger]

I'm going to go with DWM on this one , maybe people in different parts of the world use different tools , who knows..... In my extended family there are a lot of hunters , we fish we hunt he kill we clean and not one of us has ever used a flippin' axe/hatchet to skin game , man do I want to roll my eyes on this but i'll keep it nice


Actually Normark knife company(usually made by Eriksson) use to make a skinning axe just a point of interest.


Until I came here I never once heard of the term "batoning" unless a girl wearing a cheerleader outfit was nearby , batoning may be the acceptable practice in some parts of the world but I will stick to my axe or better yet, pruning shears for kindling wood ( why in the world would you baton when you can prune ).


Well unfortunately it is a technique that is highly over used now it is meant to be used as a way to cut larger pieces when you simply only have a knife but most people tend to use it now as a magic show trick or some kind of way to evaluate a blade not meant to chop with. as I have said before if you only had one match would you strike it then go build your fire why waste a valuable tool by doing what it is not inteneded for. batoning does not make you a knowledgeable knife user or a bushman for that matter knowing how to use common sense does. Your brain is your most valuable tool might as well use it.

 

[Cliff Stamp]

[lock ring failure]

Possibly or the fact that the blade is the largest one they could me that the stress placed on the area hade a greater effect.

Yes it will be greater as the torque will scale with the length. However this doesn't mean the blade would fail, it will just push the lock bar right off the blade by impacting the wood.

Impacting the spine to increase the ability to cut/split is fundamental to wood working. I have never heard it called batoning, but every carpenter is familiar with it as was discussed in detail on the Wilderness form the last time this was brought up.

http://www.bladeforums.com/forums/showpost.php?p=3912596&postcount=62

I don't understand the controversy over Vivi's testing.

Lack of experience and baselines leading to unfounded conclusions of user abuse when there is obviously a case of a horrible blade which is apparently weaker than the metal locking ring.

Seems to me a blade that fails in such a fashion against wood and it's own lockring would likely have very poor edge retention under "normal" usage.

Obviously yes. It isn't that rare to have problems reported on Opinels, most feedback is positive but you can find descriptions from people citing very poor edge retention, edge chipping readily, etc. . It isn't that surprising that the heat treatment would be varied given the other variances you tend to see in grind and edge finish.

-Cliff

 

[canranger]

[lock ring failure]



Yes it will be greater as the torque will scale with the length. However this doesn't mean the blade would fail, it will just push the lock bar right off the blade by impacting the wood.

How can you be certain of this they use Beech wood and have youtested it your self to know that a 100% of the time that is the common failor.


Impacting the spine to increase the ability to cut/split is fundamental to wood working. I have never heard it called batoning, but every carpenter is familiar with it as was discussed in detail on the Wilderness form the last time this was brought up.


I am a master craftsman when it comes to wood working I have given seminars at wood working shows throughout ontario and taught wood working classes in the U.S. A wood worker knows which blades to hit from behind and which ones you don't thats why they make chisels and I have never had to hit the spine of a plane blade.



http://www.bladeforums.com/forums/showpost.php?p=3912596&postcount=62



Lack of experience and baselines leading to unfounded conclusions of user abuse when there is obviously a case of a horrible blade which is apparently weaker than the metal locking ring.


Just because some one doesn't agree with you Cliff doesn't mean they are not experienced now, now I hope you are not reffering to me.

I think the major thing here is there are some blades you chop with and some you don't some you cut meat with and some you don't and some you carve wood with and some you don't the beauty of having so many edges to choose from is you get to buy so many. Yet again you should use them for what they are intended to do.



Abe

 

[Cliff Stamp]

How can you be certain of this ...

The same way I can be certain that if you use a file on a piece of cold rolled bar stock which one will get cut by the other and yes I have done it and yes that is the way they will fail unless of course the blade is improperly hardened as was obviously the case in the above.

I have never had to hit the spine of a plane blade.

Generally you also don't tend to impact draw knives, chip knives, scrapers, etc., but you do impact chisels, froes, hack knives, hatchets, etc. . There is also of course nothing inherently different from an impact on the spine of a blade to increase the cutting ability than simply pressing on the spine with the off hand or with the thumb to also augment the cutting ability. Both of them are achieving the exact same goal which is to provide more force to the blade and the number of applications are obviously very wide if the amount of force available is high, it basically is no different than just increasing the inherent cutting ability by the same amount.

For example, yesterday I was doing some maintenance on a gravesite when the couple next to me ran into a problem because there was damage to one of the railings but they had no nails or tools of any kind as they just came up to weed and straighten the flowers after a heavy wind storm. I took the 3.5" commons I had with me and cut them in half using a Temperance and fixed the rail. I "batoned" on the spine of the Temperance with a rock to cut the nails and because it is a skill I have employed many times before the knife was unharmed just lightly dulled because the nails were cut on a piece of concrete. You need a very hard backing as otherwise the nails can bend around the blade and this can easily take a piece out of the knife.

-Cliff

 

[hardheart]

The pic tells the whole story. What was struck is not important, just look at the way the steel reacted to the impact. The fact that it was wood points more to a problem with the materials.

It's an Opinel, too light for chopping? Well, if it's too light, then how was enough force generated to damage the blade? Because it was a poor blade. It dented, rolled, and tore; doesn't seem suitably hardened.

 

[db]

Hardness check. Take your #10 and try and scratch the #12 with the 10's tip, then do the same to the #9. Then do the same thing but use the #12 to scratch the #10 and #9. I think that should show you if its a soft blade or not. The #9 and #10 are the same steel as the #12 right?.

 

[Vivi]

There was another recent thread about batoning with an Opinel and while I respect other's rights to post a thread , I thought it was pretty silly to even consider such a task with a blade not meant for that task... An Opinel has a thin , fine blade far better suited for garden work or gutting fish , light carving or opening envelopes (my opinel performed these well) than to use it to build yourself a log cabin.

The Opinel is suited well for the tasks you mention, but it's very much capable of this type of chopping and the batoning I've done with them. In the same respect you could take an Extrema Ratio folder with 1/4 inch thick blade and obtuse grind and use it to whittle. In neither case would the knife preform as well as an optimized tool, but they are capable of carrying out the task.

It's an Opinel, too light for chopping? Well, if it's too light, then how was enough force generated to damage the blade? Because it was a poor blade. It dented, rolled, and tore; doesn't seem suitably hardened.

Exactly. Every hardened blade I'd seen get damaged would bend a little one way or the other or simply chip out. I've never seen this type of tearing before, though I don't break blades often.

Hardness check. Take your #10 and try and scratch the #12 with the 10's tip, then do the same to the #9. Then do the same thing but use the #12 to scratch the #10 and #9. I think that should show you if its a soft blade or not. The #9 and #10 are the same steel as the #12 right?.

This was interesting and further shows that the steel was improperly treated on the 12. I took a number 8 and scratched the blade face on the 12 and produced visible scratches. On the converse, the 12's tip wanted to just slide across the surface of my 8 and left no scratches that wouldnt be wiped off with a finger. Then I took the 12 and chopped into the blade of the 8. The 8 had some very small, minor chips lightly visible to the eye. However, on the 12 the 8's blade was sinking in roughly 3 times the amount the 8 was being damaged. Same effects when using the 8 to chop on the blade of the 12. Just from doing this the 12's steel feels softer to me and you can really feel the 8's blade going right into it.

Cliff is right, I've caused the lock rings to become dented and in some cases pushing into the wood, but it's abnormal for the lock ring to ever dent the blade itself.

 

[canranger]

Generally you also don't tend to impact draw knives, chip knives, scrapers, etc., but you do impact chisels, froes, hack knives, hatchets, etc. . There is also of course nothing inherently different from an impact on the spine of a blade to increase the cutting ability than simply pressing on the spine with the off hand or with the thumb to also augment the cutting ability. Both of them are achieving the exact same goal which is to provide more force to the blade and the number of applications are obviously very wide if the amount of force available is high, it basically is no different than just increasing the inherent cutting ability by the same amount. Cliff

Cliff this is a classic apples and oranges example you give those tools you speak of have blade angles between 30 and 35 degrees suited too taking the shock by adding force.

Secondly the pressure generated by pushing and impacting on the spine are not the same not any more alike then it would be if I ran into a 200lb block with my car or edged up to it and pushed it one will cause damageand the other will move the mass.

The end result is the same one way or another yes you cut the wood but how you get there is not and it will change the impact on the tools.

Yes then lets say the Opinel was improperly heat treated and who ever thouight of the scratching test good job very clever. For the sake of the knife industry may many more tests tasking blades to their limits continue so they can sell more. Do what you want with your knives but don't expect them to survive improper use and improper use is not a test.

Cliff keep posting bud it is always a pleasure to read your stuff I find it entertaining.

Abe



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