Freakingstang
Doctor Freakinstein
Lakeside53 said:
DAMMIT!
stihl chain hardness
- Thread starter JONSSTIHL
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DAMMIT!
ShoerFast
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There is a chance that this chain is not harder on one side, it could happen, but Stihl makes a lot of chain and it would be hard to believe that there is much difference from one side to the other.
But what may have happened , as it was suggested, one side did loose it's hardness and makes the other side look harder. There has been some discussion on what type of steel is used for Stihl cutters, but as a magnet sticks to it, it needs a lot of color to harden, altho I will add that most steels would air harden , air would quench most steel at 60+ MPH , if it ever did get that hot, like on Freaks Wildthinggy.
The hardness could be drawn out of a dull cutter, running at as low as 350 DEG. and rapid intervals could step up this processes, just think of how many heat-treat cycles a dull cutter would see in a short time.
If it were my chain, I would try a new file and see if it came out closer to the same number of strokes for each side..
But what may have happened , as it was suggested, one side did loose it's hardness and makes the other side look harder. There has been some discussion on what type of steel is used for Stihl cutters, but as a magnet sticks to it, it needs a lot of color to harden, altho I will add that most steels would air harden , air would quench most steel at 60+ MPH , if it ever did get that hot, like on Freaks Wildthinggy.
The hardness could be drawn out of a dull cutter, running at as low as 350 DEG. and rapid intervals could step up this processes, just think of how many heat-treat cycles a dull cutter would see in a short time.
If it were my chain, I would try a new file and see if it came out closer to the same number of strokes for each side..
Lakeside53 said:
Yup I have to agree with Andy on this one.....:hmm3grin2orange:
.
elmnut
ArboristSite Operative
blis said:
I would agree with this.
Big Woody
ArboristSite Operative
In order to work harden something it has to be loaded past the yield point. There would have to be some corresponding permanent plastic deformation to the cutter tooth as well in the work hardened region. Mild steel has a yield point of 36,000 psi. Hardened steel probably between 50 and 100. I would say that is impossible in a chainsaw tooth hitting wood at any speed. Especially for a "dull" cutter.
Likewise the temp. of the chain during cutting would have no effect on the mechanical properties of the tooth. Way to low as mentioned above. High temp causes thermal softening but not out in the woods.
Lakeside53
Stihl Wrenching
Big Woody said:In order to work harden something it has to be loaded past the yield point. There would have to be some corresponding permanent plastic deformation to the cutter tooth as well in the work hardened region. Mild steel has a yield point of 36,000 psi. Hardened steel probably between 50 and 100. I would say that is impossible in a chainsaw tooth hitting wood at any speed. Especially for a "dull" cutter.
Likewise the temp. of the chain during cutting would have no effect on the mechanical properties of the tooth. Way to low as mentioned above. High temp causes thermal softening but not out in the woods.
O.k., so explain why beaten up cutters are too hard to file... and not so when not abused...I still go with the work-hardening theory.
elmnut
ArboristSite Operative
Lakeside53 said:
Cutters are harder to file when beaten up due to heat caused by friction. Lakeside is right on! There is a thread here somewhere that claims cutters are chrome plated! Chromoly content refers to the chromoly content of the cutter not the sparkle. Chromoly is the result of mixing materials, chrome is a plating process. Annealing is a process where steel is heated and then cooled according to a set guidline. I may be wrong, but who cares. I am just happy that I am not on roofersite.com!
elmnut
ArboristSite Operative
Lakeside53 said:
Cutters are harder to file when beaten up due to heat caused by friction. Lakeside is right on! There is a thread here somewhere that claims cutters are chrome plated! Chromoly content refers to the chromoly content of the cutter not the sparkle. Chromoly is the result of mixing materials, chrome is a plating process. Annealing is a process where steel is heated and then cooled according to a set guidline. I may be wrong, but who cares. I am just happy that I am not on roofersite.com!
elmnut
ArboristSite Operative
Hard to argue with the double post, double post.
Big Woody
ArboristSite Operative
It is really non-productive to argue points like this. This type of a statement is totally subjective (as opposed to objective). Two different people could reach opposite conclusions on the same chain.
If you have Knoop and Vickers results, that would be a different story.
Lakeside53
Stihl Wrenching
Sorry If I appeared argumentative - not my intent.
The statement might be subjective, but filing a hardened chain isn't... it's very real, and we get them every day so it's easy to tell one from another - the file literally skids past the cutter. Something is certainly making them hard. Once cut back, the tooth is softer again.
The statement might be subjective, but filing a hardened chain isn't... it's very real, and we get them every day so it's easy to tell one from another - the file literally skids past the cutter. Something is certainly making them hard. Once cut back, the tooth is softer again.
Big Woody
ArboristSite Operative
Here is another example of a subjective observation from another post today on AS. According to his observations Husky chain is way better than oregon chain. :bang:
I'll bet you could get a couple of cases of beer of this logger since he is convinced by his subjective observations about the chain. Probably wouldn't even believe it was the same chain if you had proof.
I'll bet you could get a couple of cases of beer of this logger since he is convinced by his subjective observations about the chain. Probably wouldn't even believe it was the same chain if you had proof.
Lakeside53
Stihl Wrenching
On shagbark hickory too... 
Monkeyhanger
ArboristSite Guru
Lakeside53 said:
Hi,
this may be a mild form of impact hardening, I can't think of any other reason for it that makes sense. A hot chain would get softer rather than harder but if the teeth hit something hard then that may be different.
For an example to try at home take 1 largish stone and a newly sharpened axe. Then hit the stone HARD with the axe. Then whilst resharpening the axe notice how extremely hard the area around the damaged edge is. That is the impact hardening, something similar is also used to harden the surface of motorcycle chains. This could also happen with a saw chain when it hits a stone, I'm not 100% sure but it seems very likely to me.
I don't know the proper name or terms for it but it is a very real occurance.
Bye
JONSSTIHL
ArboristSite Operative
I believe that would be a primitive form of shot peening, but it makes sense as an explanation in this context
JONSSTIHL
ArboristSite Operative
as an explanation in the context of the last page of this post but not to explain the original post just to clear that up but i'm learning more every day.
and I'm not saying that to bring the post back on track (I really should think before I type)
I'm perfectly happy with where this post has gone. I think I will practice my technique and pay attention when I switch sides
thanks
and I'm not saying that to bring the post back on track (I really should think before I type)
I'm perfectly happy with where this post has gone. I think I will practice my technique and pay attention when I switch sides
thanks
ShoerFast
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JONSSTIHL said:
Shot peening is more of a form of surface texture, or a stroke of a good file. What would harden the edge of an axe hitting a rock or a rocked out chain is called "edge packing" , like shot peening, with a little depth, but should come out on a few strokes of a file.
Edge packing would only be slightly past the actual damage, as it is really just metal folded into it's self. Also part of the reason why forged anythings are usually stronger then any other method.
1953greg
ArboristSite Guru
i sawed 3/4 way through a deck screw once w/ a new chain. file would only zing across the cutters after that. took bout half the tooth off w/ the bench grinder before a file would cut it. dont know how/what happened but the chain was only sharpenable w/ the grinder for a long time.
ShoerFast
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That deck screw could have set the cutters back into them self?
What a heat treat dose is change the molecular structure to take advantage of the elements of steel. Simplified, aligning the molecules with the carbon to set a harder structure. What edge packing dose is makes a denser structure.
Take a quality drop-forged or extruded socket or wrench and drop it into your hand, the density is readely felt.
What a heat treat dose is change the molecular structure to take advantage of the elements of steel. Simplified, aligning the molecules with the carbon to set a harder structure. What edge packing dose is makes a denser structure.
Take a quality drop-forged or extruded socket or wrench and drop it into your hand, the density is readely felt.
Tzed250
Addicted to ArboristSite
Well...
Shot peening is designed to toughen the peened surface to reduce crack propogation. It is done to connecting rods for this very purpose. If the metal is "moved" and not just worn, then work hardening can occur. The hardness has nothing to do with the temp of the cutter. Steel is hardened during a quenching process when the carbon molecules react at the surface. This is why low carbon steel (less than .02%) cannot be hardened unless it is carburized, or subjected to another additive process.
Shot peening is designed to toughen the peened surface to reduce crack propogation. It is done to connecting rods for this very purpose. If the metal is "moved" and not just worn, then work hardening can occur. The hardness has nothing to do with the temp of the cutter. Steel is hardened during a quenching process when the carbon molecules react at the surface. This is why low carbon steel (less than .02%) cannot be hardened unless it is carburized, or subjected to another additive process.
