Grind cutters down to "witness mark" OK? Safety?

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Billy_Bob

Billy_Bob

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How far can you grind down the cutters on a chain and still use the chain safely?

Grind all the way down to the "witness mark"? Or something less than that?
 
Edge & Engine

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I've seen chain ground a good ways past the witness mark with probably 95% of the cutters still on. That said, it did NOT cut well at all, and I wouldn't recommend it.
 
redprospector

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You can grind them till the teeth start breaking off and not be in much danger.
A chain seems to me to get faster as it's filed back, to a certain point. After that it starts going down hill pretty quick. So to me it's not worth taking the teeth back that far.
I've noticed (in race chains) that when a tooth breaks off it will stick in the log, taking out several teeth behind it.

Andy
 
computeruser

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Some of my faster chains are the ones at the end of their lives. Assuming correct angles, they still hold an edge properly, clear chips beautifully, and touch up with a file just fine - lots of room to work. Now, they may worry Woodie a bit when they get ground this far back, but even he will agree that they can cut!
 
litefoot

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My local Stihl dealer must think the witness marks are the same as crosscut marks on a piece of lumber. Not much left after he gets done "grinding" a rocked chain. He did one chain for me. He will never do another.
 
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