Chain

[BCinVT]

I have a Stihl 290 Farm Boss with a 20" bar.My question is,Do I always have to put the same type chain on the saw?For example,The chain that came on this saw is a 81 drive link chain.Do I always have to use a 81 drive link chain?Seems like I've put a different chain on my Husky 350 than was originally on it.Probably a dumb question,but nobody around home could answer it for me, some said you have too,and others said you could put any 20" chain.Thanks

[GlenM]

Whatever chain you use, must be compatible with the bar and the sprocket.
g

[Rocky_J]

The first thing you should do is learn chain sizes (pitch and gauge). There are three common pitches and three common gauges. Once you understand pitch and gauge, then the other nonsensical questions will be answered as well.

Pitch is the length between the chain drivers (the tangs on the inside of the chain that ride in the bar groove). It is typically measured by taking the distance between 3 rivets and dividing by 2. The three most common chain pitch sizes are
3/8" lo pro (for small saws typically below 40cc)
.325" (typically found on saws from 40cc to 55cc)
3/8" normal, full sized chain found on most saws from 55cc to 100cc
There is also a larger size, .404", found on the biggest saws over 100cc and on mechanical harvesters. You will likely never see or use this size.

Once you figure out which pitch chain you have, then the other important size measurement is the gauge. This is simply the thickness of the drivers (the part of the chain that rides in the bar). There are four common driver sizes.
.043" is the thinnest gauge, only found in 3/8 lo pro chain for the smallest of saws. It is also used on most pole pruners.
.050" very common gauge
.058" common in certain parts of the country.
.063" mostly used by Stihl to keep users from being able to buy other brand replacement chains unless they buy new bars as well.

Sorry, gotta run. I'll let you digest that and will pick this back up later.

[tonto]

Dan'g Rocky. That is the best explanation I have even seen. Very informative for us weekend warriors. You sure you weren't a school teacher in a previous life? Thanks, Tonto.

[Ed]

.063" mostly used by Stihl to keep users from being able to buy other brand replacement chains unless they buy new bars as well.

LMAO.....

Good description.

Ed

[ladylake]

Stihl would do something low down like that.   Steve

[BCinVT]

Thanks for the info guys.I know that I have to stay with the .063 chain,but was wondering if the amount of drive links matter?Also,if I could go up to the 3/8" normal chain on my saw.The chain on it now is the .325.Also,how can I find out what size file to buy for it?It doesn't say in my manual.Thanks

[ladylake]

 Stick with the .325 on a MS290.  Steve

[windthrown]

Thanks for the info guys.I know that I have to stay with the .063 chain,but was wondering if the amount of drive links matter?Also,if I could go up to the 3/8" normal chain on my saw.The chain on it now is the .325.Also,how can I find out what size file to buy for it?It doesn't say in my manual.Thanks

Yes, the number of drive links matters greatly. You need to stick with the same number of drive links for your new chain loops on that bar. You also need to stick with the same type of .325 chain using that bar with the sprocket you have. The bar and sprocket (both the saw sprocket and nose sprocket) are set to drive only one one type of chain, which in your case is .325. In order to run 3/8 standard chain (which works just fine on a 290 BTW; I run my both my 290 and 310 with 3/8 bars and chains)  you need to swap the bar and drive sprocket to a 3/8 standard size. The file size for a .325 chain is 3/16 of an inch. It is fairly common.

[Rocky_J]

Thanks for the info guys.I know that I have to stay with the .063 chain,but was wondering if the amount of drive links matter?Also,if I could go up to the 3/8" normal chain on my saw.The chain on it now is the .325.Also,how can I find out what size file to buy for it?It doesn't say in my manual.Thanks

The number of drive links determines the length of the chain. How can you use a different length chain unless you buy a different length bar? You only have a certain amount of adjustment in order to take up slack.

The pitch, gauge and chain length will be etched in the square information panel on every Stihl bar. The gauge will be in metric rather than in inches. Take a close look at it and see how the information is written.

Windthrown gave good advice also. Read his post again.

[Ed]

Even 1 link of chain will keep a chain from working or not working on a saw. If you have the same gauge chain, the difference in pitch (.325 to .375) will not allow you to interchange. You have to have the correct sprocket on the saw and the correct sprocket tip on the bar.

Ed

[downeast]

Kuddos. Nice job with a clear K.I.S.S. explanation Rocky & Wind.

Remember to rotate the bar after every sharpening: it evens the wear. ("STIHL" looks best upside down anyhow.  )

[Rocky_J]

And we haven't even begun to touch on the different style cutting teeth on various style chains. But the shape of the cutters on the top side of the chain has nothing to do with whether or not it will fit on the bar and sprocket on your saw. 

[windthrown]

Kuddos. Nice job with a clear K.I.S.S. explanation Rocky & Wind.

Remember to rotate the bar after every sharpening: it evens the wear. ("STIHL" looks best upside down anyhow.  )

And don't forget to file those rakers down.

I was also going to mention that if you get a lot of chain stretch, like when using low profile 3/8 Picco baby chains, they can stretch to the point that they can run out of the adjustment range of the saw. In that case you can remove a link from the chain and use it on the same bar. Which is why I stated that the number of links is always the same for a "new" chain. 

[des170stihl]

Please take note that any Stihl Brand chain is pre stretched from the factory.

[maple flats]

Removing a link is dangerous unless you know how to determine what the rivet wear is and can be sure it is still safe. Most casual users would not be able to do such. When a chain stretches to much to tighten, throw it away. The rivets and rivet holes are warn too much. If that happens too soon, check the chain and bar oil. Are you using a bar oil or subbing something else? Is the oiler working properly?

[BCinVT]

Great info guys.I would not try to remove a link,because I don't feel that confident about doing that.How many times can you file the chain before it's to worn to use?Just asking because I hit a couple of nails in a big maple I was cutting today,and now I need to sharpen my chain.I have another chain,but don't know if there are any more nails in the tree,so I hate to put the new chain on until I'm done with this bunch of trees.Sure does tick you off when you see those sparks coming off your chain 

[Rocky_J]

You can sharpen the teeth on the chain until there are practically no teeth left. As long as you maintain the correct angles and bring the rakers down to the proper height as you file the teeth back, you can keep filing until you can't file any more.

The Stihl chain (and some of the Oregon chain) will have a scribe mark on each tooth. This serves two purposes, it is a guide to help you file at the correct angle and it is also the furthest back that they recommend you file the tooth.

[windthrown]

Please take note that any Stihl Brand chain is pre stretched from the factory.

What the heck is that supposed to mean? They continue to stretch on a saw. I run mostly Stihl chains myself.

As for removing a link from a 3/8 low profile chain, no big deal. I have done it several times and had saws shops do it as well. As many times as I have thrown and broken chains... its not like it is gonna kill you.

[Rocky_J]

windthrown, it means that if you take a brand new Stihl chain and an identical size brand new Oregon chain and lay them side by side, the Stihl chain will be longer. But when you put them on the saw and run them, the Stihl chain will need minimal adjustment in the first few tanks while the Oregon will need to be adjusted a few times to take up the stretch. After an hour of use, both chains will be about the same length.

One other benefit of the Stihl chain is that it minimizes wear on the drive sprocket and bar tip because the distance between links varies much less over the life of the chain. The Oregon chain will be tight on the sprocket when new and loose on the sprocket when worn so it wears a wider profile on the sprocket teeth. My sprockets last a lot longer with Stihl chain.