Stihl 291

You need to know if your pitch is 3/8" or .325"...look on bar or sprocket.

You can check what will fit here: http://en.oregonproducts.com/pro/lookups/selguide.aspx?BusId=OCS&SellReg=USA&LangId=ENG

You can read the data off the bar:

A bar needs the chain to match 3 things: PITCH, GAUGE, DRIVE LINKS (DL)

And if you want a Stihl bar, stop by your dealer:

STIHL ROLLOMATIC E Standard
- laminate bar that comes with most Stihl saws
- low kickback model (green)

STIHL ROLLOMATIC Super E
- solid steel bar
- professionals prefer, easier plunge/bore cutting
- standard model without low kickback features (yellow)
- easily replaceable tip sprocket

It's easiest to use online bar & chain finders (just enter your make & model); however, you can find a replacement bar (any brand) without them.

You must match all these items:

BAR MOUNT PATTERN
PITCH
GAUGE
NO. OF DRIVE LINKS (DL)
KERF SIZE (NK) - sometimes relevant

Unbolt your bar from your saw's powerhead and look at the stamp near the bar mount. It will tell you PITCH, GAUGE and DL you need to look for in a new bar. It often has additional information for the bar model.

BAR MOUNT PATTERNS have numbers/codes, but it's easiest to look at a compatibility chart or look on the new bar's packaging to see if your particular saw is listed as being compatible.

KERF SIZE is important for some saws, usually 50cc or smaller saws in .325 pitch. If you have an NK chain, then you MUST run it on an NK bar. You can run standard kerf chain on either a standard kerf bar or an NK bar.

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SIDE NOTE: Since chainsaw drive sprockets are gauge independent, you actually can switch to a different gauge in your new bar if you wish. Your new chains for that bar, of course, will also have to be in the new gauge.