should this happen??

G

grobe

Joined
Aug 18, 2005
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228
i took a hard use, drop point camp blade 7.5 inces long and .25 inch stock. i chopped a 4-5 inch diameter log (apple or pear i think), split the log by battoning the blade through and then the fun part. i layed the split half, inside up, and stabbed the blade tip into the center. then battoned the pommel to drive the tip in further. stradling the log with me feet holding down each side, i gripped the handle and twisted right and left in a drilling fashion. i then started to pry forward and backward. next thing i heard was "tink". the tip had snapped off in the wood. i wasn't using very much force at all. the wood didn't even give. it snapped off .5" of the tip just below the surface of the wood. i took the log apart and checked for foriegn objects or knots and there was nothing.

so, is this abuse or was the heat treat off?? in my mind a hard use knife should be able to handle this and more. does this surprise anyone??
 
If you are trying to break a knife, or any material object, you will probably be able to do just that.

What were you actually trying to do, and when would you have stopped? When would you have decided your actions did constitute abuse?

Your question would make more sense if we knew who made the knife and out of what kind of steel. Anybody can claim their knife is for hard use, but some are acknowledged to take more than others.
 
grobe said:
then battoned the pommel to drive the tip in further.
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How far was the tip in the wood, more than an inch? Does the point have a slim distal taper, is it a tool steel or stainless?

i then started to pry forward and backward.
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With your arm or bodyweight?

it snapped off .5" of the tip just below the surface of the wood.
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How thick is the blade at the break, is there any bend in the steel or does it fit together perfectly?

-Cliff
 
Type of steel would help, however, knives are not made to be used in a "twisting" or "prying" fashion. It's hard to tell from your description what the blade should have endured. Everyone has a perspective on how much is TOO much pressure. The only knives I would use in that manner are ones I really wouldn't miss if they broke. I am a bad example though.... I love all my knives. Old, new, in style, and out. One good ??? to ask yourself is.... could I have done the task with less risk using something else in my kit???? If the answer is yes.... use it next time.
 
i was just trying to test the blade and dig in the wood a bit. i used only arm strength. i've done this with other knives and have seen flex. this didn't flex and there is no bend just a clean, top to bottom break. its 5160 which i understand to be quite durable. the tip was in just over a half inch.
 
A half an inch is low and it broke right off at that point which is odd, it should break much further down in the wood, as wood will compress allowing the part near the surface to bend. 5160 should also have a lot of give to it as well. The only way I can see this is if the maker ran a fine distal taper and for some reason adjusted the heat treat on the steel to run it near max hardness.

-Cliff
 
Did the maker differentially temper the blade? Also, does it have a full distal taper to it? Do yo know the RC hardness of the blade?
 
its not differentially tempered that i know of, but i don't feel that should matter as it wasn't under very much stress.
 
Actually, differentially tempering should help. This tempering process helps the blade to flex. However this is a complicated process. If done wrong..... it could weaken the blade. The blade did break further from the tip than normal. Do you know how hard the blade is (56-57 rc being soft 61 rc or above being hard for a blade)
 
58 rc. i understand the theory behind differential tempering, just didn't think it would make much difference that close to the tip.
 
I suspect the tip bent first maybe even a second time and then broke. Sounds to me like you really leaned into it enough to do that to it. Guess you will be doing some reprofiling now.
 
actually the maker is replacing the blade for me. as i said earlier, i didn't use very much force at all. i've used more force on the tip of my mora clipper.
 
grobe said:
58 rc. i understand the theory behind differential tempering, just didn't think it would make much difference that close to the tip.
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I'm sorry. I didn't read your previous post (58rc). If it was differentially tempered wrong, it would make a huge difference. Could be why it broke. Thats why I asked. I am assuming it is a custom knife???? If so, can you take it back to the maker and have him re-profile the blade. I hate to hear someone has a broken knife. I know how I would feel:mad:
 
grobe said:
actually the maker is replacing the blade for me. as i said earlier, i didn't use very much force at all. i've used more force on the tip of my mora clipper.
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Glad to hear it. :)
 
could i expect this from a ratweiler?? i'm thinking of getting one if the replacement can't handle this type of work.
 
A distal taper is where the blade thins gradually from near the handle to the tip. Most blades are not fully tapered and are full stock for a lot of the blade, some have no taper. If the blade slimmed out radically through the tip and was for example 1/16" thick at 0.5" back where it broke then it isn't unrealistic for it to break. However it should be very flexible when it gets thin which is why I think you described a problem. If it was similar to the force you used on the Mora Clipper then it is pretty obvious it is a problem unless the knife was ground to a similar thin point profile.

-Cliff
 
thanks cliff-
the blade is .25" out to where the 'drop' starts towards the point. the blade style is very similair to a busse steel heart, although i've never seen a steel heart so can't say whether the tip is the same thickness. in my mind it was a flaw. i just can't see a tip snapping that easily.
 
Beginning blade makers sometimes have that problem and it's usually due to over heating the tip. Over heating is very easy to do with a torch and results in large grain size and subsequent brittleness !
 
any onpinions on how a ratweiler would fare with this type of situation?? i don't think this is an unreasonable task to ask of a hard use blade. the knife i was using is often compared to a camp tramp but i like the micarta on the ratweiler better.
 
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