How many times can you sharpen a chain before its been sharpened so much there's not enough left to sharpen?
I sharpen mine until the teeth start breaking off when cutting. So pretty much down to nothing. I like to get my money’s worth out of them.
Keep on sharpening until there's no more toofs left to sharpen...as far as how many sharpening's that is...depends on how bad the chain is, and who is doing the sharpening, and with what type of tool...