Stretching chains

[cutter88]

Can somebody please tell me what the main cause of stretching is... Iv had 2 chains this month on 2 different saws stretch beyond tightening before they are Half worn out ???

[Al_Smith]

What brand of chain ?

[AdkStihl]

Inferior materials.
My guess is Oregon or Carlton chain.
But that's just a guess.

STIHL chain is advertised as being pre-stretched and doesn't seem to stretch much at all.

[sawguy21]

. We need to know brand of chain, what you are cutting and whether you are properly sharpening. Lack of lubrication is a common culprit

[cutter88]

Stihl semi chisel chain the stuff with semi round tooth for cutting dirty wood... Cuts maple, oak, ash on a 2186 Jonsered and ms461 stihl and I would say I'm a good sharpener... And for oil we use strained used 15w40 been doing that for years never had chains stretch

[pineywoods]

Stretching chains is actually a mis conception. Chains don't actually stretch. What happens is the rivets and the holes for the rivets wear (soft metal, lack of lube, dirt and grit, etc). Look at it this way, most 20 inch chains contain around 72 drive links. Each link will have at least 3 rivets. If each rivet only wears off a thousandth of an inch, that's a total of .021 inch of what appears to be stretch but really isn't. Keep um lubed and out of the dirt....

[beenthere]

pineywoods answer good. 

Look for how your chains are wearing... and then the reason they wear so quick.

[OneWithWood]

The used motor oil lacks any additive to help it stick to the chain so it flies off the tip and the chain on the underside of the bar becomes dry.  I learned this the hard way as I used to use reclaimed motor oil as a bar lube.
Another culprit is pinching the chain in the cut and racking it back and forth to loosen it.  Accelerates the pin wear beenthere mentioned.
Not loosening a chain after running hard and hot will also accelerate the pin wear.

[SawTroll]

Stretching chains is actually a mis conception. Chains don't actually stretch. What happens is the rivets and the holes for the rivets wear (soft metal, lack of lube, dirt and grit, etc). Look at it this way, most 20 inch chains contain around 72 drive links. Each link will have at least 3 rivets. If each rivet only wears off a thousandth of an inch, that's a total of .021 inch of what appears to be stretch but really isn't. Keep um lubed and out of the dirt....

Yep, that's what it really is about. Too little bar oil will speed up the wear prosess.

[cutter88]

Yes I new that's what was happening... :) but thanks for the info I think ill switch to chain oil from now on and see what that does... Thanks again or the input guys

[Southside]

Never really thought of why it happens but thanks for the info.  Question - why do cutters on one side or the other of the chain wear faster than the other side? 

[Al_Smith]

Several reasons .The bar rails could be worn off slghtly a tilt .
The fix for that is to file it back straight,use a belt sander etc .

More commonly the chain cutter angles could be off. More often an error in hand filing .Plus it's a natural tendency for a person being right or left handed to file heavy on one side .Use of a guide will often correct that problem .

[tgalbraith]

one more cause of premature chain failure is the drive sprocket. It wears too, and after awhile the full force of
cutting gets concentrated on one cog..  I replace my drive sprocket after about the fifth chain. 8)

[SawTroll]

one more cause of premature chain failure is the drive sprocket. It wears too, and after awhile the full force of
cutting gets concentrated on one cog..  I replace my drive sprocket after about the fifth chain. 8)

I don't think it would hurt to replace it a bit more often than that - but it does of course vary with a lot of factors.

[Andyshine77]

Whenever I see a chain with that much slop it's do to an absurdly dull chain. As soon as the OP said dirty wood, we had our answer.

[Al_Smith]

I 've yet to figure out the big hulaballo of filing a chain like it's rocket science .IMO a sharp chain is more important than a hot rod saw .It's not a hard concept to grasp .

[7sleeper]

I 've yet to figure out the big hulaballo of filing a chain like it's rocket science .IMO a sharp chain is more important than a hot rod saw .It's not a hard concept to grasp .

To be honest, in my experience, the concept is very hard to grasp for a very large portion of chainsaw users I have met...

7

[thecfarm]

It is hard to grasp. It takes time to understand what to do.I destroyed a few chains trying to grasp it. And I had My Father to watch and show me. He gave up on me. He could sharpen a saw. He did not like any of us kids to run the saw. He was not concerned about the saw,just the chain. He just knew we would hit the ground with it.

[cutter88]

I can sharpen a chain real good.... Doesn't explain why the odd one stretches

[Tug Hill Walt]

Bad lube and very dirty wood will cause wear on the pins to the point that the drive sprocket wears out. From experience of buying a load of fuel wood logs full of fine silt and mud. Only got about 15fc out of a chain and was constantly sharpening. If you can pressure wash the wood.

[Al_Smith]

Well I'm out of ideas unless the chain was kept tight as a bango string .However were that the case it wouldn't cut correctly and the bar would suffer . ???

[John Mc]

one more cause of premature chain failure is the drive sprocket. It wears too, and after awhile the full force of
cutting gets concentrated on one cog..  I replace my drive sprocket after about the fifth chain. 8)

I don't think it would hurt to replace it a bit more often than that - but it does of course vary with a lot of factors.

So how do you tell when a sprocket is actually too worn to continue using? I'd rather replace it depending on condition, rather than after so many chains. I've seen some that obviously should have been replaced long ago, but when it's not so obvious I'm not sure what to look for.

[Al_Smith]

The slots in the rim become elongated .It will start to cut a groove around the center of the rim .

If you let one go too long not only will it stretch the chain but you take a chance of the rim failing .I did once and only once and had to replace 4 drivers on a 32" chain loop .They're inexpensive ,about 5 bucks a pop .

[HolmenTree]

Rim sprockets with too many chains run on them will stretch a new chain quickly.
Todays rim sprockets have wear indicator marks embedded in the rims radial surface with 2 wear marks per tooth.

When the marks are worn away by the chain, it's then time to change the sprocket.
Keep an eye on badly worn bar nose sprockets too.

[John Mc]

Are the wear marks the small notches perpendicular to the edge, about centered on each of the drive slots?