How often should chain be sharpened?

Usually I touch it up one pass per tooth every tank of gas and that keeps it nice and sharp. I will take 2 or more chains on a big cut day and swap them because its faster then bring them home dull and hit them on my bench sharpener as well.

Pete

I rotate 3 chains - as soon as one feels dull, I either stop cutting and sharpen, or switch chains if I still have work to do. The best advice in my opinion is to stop cutting when you feel like you are 'pushing' the saw into the wood. If the saw isn't pulling you into the cut and you are working the cut too hard, time to sharpen/switch chains and give the saw a break. No need to make the saw worker harder than it needs to. Cheers!

Depends on the wood you cutting, cleanliness of the wood, making sure your keeping the chain out of the dirt, and so on. I do mine as needed following what NH_Wood said above.

When you are no longer happy with the performance of the chain, sharpen.

The "official" rule of thumb is to touch up after every tank of gas but honestly, I can say while bucking up large trunks, I'll burn a helluva lot more than 1 tank before I notice the chain getting dull. Then again, I've had trunks that I had to sharpen/swap several times and not even burn 1 tank.

Rough guideline?
Get used to "your saw" with a sharp chain. Look, listen & feel. How's it sound, the chips look long & big,
You have to hang on when you pull the trigger, it wants to pull hard. Cutter tips look & fell sharp.

Performance: cutting time has dropped off on similar sized rounds. If easy to pull the saw out of the cut when running, getting dull.

Sound: RPM stays high when in the meat of the cut where before it would get that low growl & just eat wood.
Many here can be out cutting & hear another saw running & know it has a chain problem from the sound

Eyeball: Look at the chips it's spitting out now & then, saw dust is not good, should be spitting out chips.
wood chips stack up fast with a sharp chain, Chips not saw dust.
Tips of the teeth are hard to see, no shiny spots usually mean it's sharp. See shiny tips, time to sharpen.
Smoke or steam off the cut or chain means it's getting hot, which many times means dull.

Best way is monitor all 3. Know what each is like when the chain is new & sharp.
Will get to be a habit, you'll notice it getting higher rpm, you'll feel how the sharp saw wants to pull into the cut & when dull it don't. Seeing saw dust is a sure sign it's dull.

After a while you won't even think about it, You'll know you have a dull chain. You'll decide if you want to finish up with a dull chain ,
or have enough left to cut that it'll be faster if you sharpen or change it out

1/2 cord or so from tree to rounds, a touch up with a file never hurts. Justifies a well earned break too.

Well said, Dave.

I bucked a maple trunk over the summer that had me touching up after every round. Of course, I was refueling as well. It was a five footer, and I couldn't make two cuts on one tank

Roughly 70% of what I cut is dead Red/Black Oak,with another 20% White/Bur Oak,with a little Shagbark Hickory & Mulberry for good measure.Most is very dry & quite abrasive on chains.Normally the chain gets 2-3 strokes per tankful,but on most of that stuff the teeth get touched up sooner.On the really dense stuff the chips arent as big even with a new or razor sharp full chisel chain.I know semi- chisel holds an edge longer in that stuff,but I still prefer the faster cutting a full chisel gives you.Its nice to take a 5 minute break when cutting,few passes with the file is actually relaxing to me.

I touch up with every other tank of gas. That guarantees a ten minute break for me. Everything I cut is oak: Water oak and Pin Oak, mostly. By the second tank, the chain needs to touched up. I do all my sharpening by hand but take the chains to nearby Stihl shop after several hand sharpenings.
$5 per chain makes them like new again.

You will learn the feel of the saw with both a sharp & dull chain. One touch with the ground or a rock in the bark throws the one tank rule out the window, but it is a good guide if all goes well.

Lately, we have been bucking up a bunch of logging "off cuts".. have needed to sharpen after only a couple cuts sometimes. The bark is full of crap from having been dragged out of the woods by a skidder..

But today I bucked two big maples, 18" - 36" rounds, made about 40 cuts I guess, chain was still pulling big chips when I was done.

(hey, who doesn't like big wood pics...)