Got 2 new chains and a file tonight. Have been using the same chain for several weeks without sharpening. Learned why that is a failed idea. Shouldn't happen again. I can dress the chain with my file everytime I go out to cut and have enough chains that every 6 months or so can drop off at the dealer for a pro-sharpening. Going to the dealer is like the toy store for adults. So many things I'd love to play with in there from leaf blowers to trimmers to 660s and 880s.