Stihl Chainsaw Chain Replacement Guide: MS170, MS250, MS311 and More

Stihl® makes some of the best-running chainsaws on the market, but replacing the chain through a dealer can cost $25–35 per chain. For homeowners running through one chain a year that's tolerable. For arborists, firewood cutters, and property owners on a working acreage — that math falls apart fast. This guide covers everything you need to know about replacement chains for Stihl saws: identifying your spec, choosing between OEM and aftermarket, and installing the chain correctly.

How to identify your Stihl chain specification

Every chainsaw chain is defined by four numbers: length, pitch, gauge, and drive link count. Mix any of them up and the chain either won't fit or won't run properly.

1. Bar length

The cutting length of your bar — measured from the front of the saw housing to the tip of the bar. Common Stihl lengths are 14", 16", 18", and 20". This is usually printed on the side of the bar itself.

2. Chain pitch

Pitch is the distance between three consecutive rivets divided by two, measured in inches. For Stihl saws, the most common pitches are:

• 3/8" LP (Low Profile) — used on MS170, MS180, MS181, MS230, MS250, and most homeowner-grade Stihl saws
• 3/8" (full profile) — used on larger Stihl models like the MS311, MS362, MS391
• .325" — found on some mid-range and older Stihl saws
• .404" — rare, mostly on very large Stihl logging saws

3/8" LP and 3/8" are not interchangeable — the cutter profile and drive sprocket are different.

3. Gauge

Gauge is the thickness of the drive link tang — the part that sits in the bar groove. Standard gauges are .043", .050", .058", and .063". The vast majority of consumer-grade Stihl saws use .050". The gauge must match your bar exactly. Too thin and the chain wobbles in the groove; too thick and it won't seat at all.

4. Drive link count (DL)

Count the number of drive links (the tooth-like protrusions on the underside of the chain). Stihl chains by bar length:

• 14" bar — typically 50 or 52 DL
• 16" bar — typically 55 or 56 DL
• 18" bar — typically 62 DL
• 20" bar — typically 72 DL

Some bar lengths have multiple DL counts depending on the model year and bar variant. Always confirm by either reading the stamp on the bar nose or counting drive links on your old chain.

Stihl OEM vs aftermarket: honest comparison

Stihl® sells OEM chains under the RM (Rapid Micro) and RS (Rapid Super) series. These are good chains. They also cost two to three times what comparable aftermarket chains run. The question worth asking: is the price difference worth it for your use case?

What you actually pay for with OEM

• Brand consistency. Same factory, same QC standards, predictable batch-to-batch quality
• Dealer support. If something fails under normal use, your Stihl dealer typically replaces it
• Bar match guarantee. Stihl OEM chains are designed for Stihl bars, so the fit is exact

What aftermarket chains offer

• Lower per-chain cost — typically 50–70% less than OEM
• Bulk packaging — most quality aftermarket brands sell in 3-packs so you have backups on hand
• Same core specs — a properly-made aftermarket chain in 3/8" LP .050" 56DL runs on the same bar and sprocket as a Stihl OEM chain in the same spec

When OEM makes sense

If you use your saw once or twice a year for storm cleanup, OEM is fine. The single $25 chain might last you 3–5 years. The convenience of buying it the same day at your Stihl dealer outweighs the savings.

When aftermarket makes sense

If you go through more than one chain per month — firewood season, an active arborist business, land clearing, or a working property — the math shifts hard. Three aftermarket chains in a pack often costs less than a single OEM chain at the dealer.

The cutter profile matters more than the brand sticker. A full-chisel chrome-plated cutter cuts the same in oak whether it's stamped Stihl, Oregon, or ALBO — provided the chain is made to spec.

Stihl model compatibility chart

Here's a reference table for the most common Stihl saw models and the chain specs they take. This covers Stihl's homeowner and light-pro lineup — the saws most likely to be running on a property or in a small landscaping business.

Stihl ships some saw models with multiple bar length options from the factory — always verify the actual bar on your specific saw, not just the model number.

How to install a new chainsaw chain

Installing a new chain on a Stihl saw is a 10-minute job once you've done it twice. Here's the sequence:

What you need

• Your replacement chain (matching your bar's pitch, gauge, and DL count)
• The bar wrench (the T-shaped tool that came with your saw)
• A clean rag and a small brush
• Gloves (highly recommended — cutters are sharp)

Step 1 — Remove the side cover

Unscrew the two nuts on the side cover with the bar wrench. Lift the cover off and set it aside.

Step 2 — Remove the old chain and bar

Release tension on the old chain by turning the tensioning screw counterclockwise (it's the small slotted screw on the front of the saw, accessible once the cover is off). Pull the bar slightly forward off the studs. Lift the old chain off the sprocket and out of the bar groove.

Step 3 — Clean the bar groove and sprocket

Sawdust, oil residue, and bar oil sludge build up in the bar groove. Use the brush or the corner of your rag to clear it. A clean groove means the new chain seats correctly and gets oil properly. Wipe down the drive sprocket too.

Step 4 — Inspect the bar

Look for burrs on the bar rails. Run your fingernail along the edge — if it catches on raised metal, flat-file the burrs smooth. A worn-out bar will eat a new chain in days. If your bar rails are deeply worn, replace the bar at the same time as the chain.

Step 5 — Install the new chain

The cutters on the top of the chain (when seated in the bar) should point forward, away from the saw body. This is the most common installation error — a chain installed backwards will not cut.

Drape the chain over the drive sprocket first, then lay it into the bar groove starting at the back near the sprocket and working forward to the bar tip. Slide the bar back onto the studs, keeping tension on the chain so it stays seated in the groove.

Step 6 — Adjust tension

Hand-tighten the side cover nuts so the bar is held in place but you can still move the chain by pulling it around the bar. Turn the tensioning screw clockwise to take up slack until the chain pulls firmly into the groove but you can still move it around the bar by hand with a leather glove. A correctly tensioned chain has the drive link tangs fully seated in the bar groove with no sag underneath.

Step 7 — Tighten and test

Lift the bar tip slightly while tightening the side cover nuts fully. Spin the chain by hand to check it moves freely. Start the saw at idle and let it run for 10–20 seconds, then shut down and re-check tension — a new chain stretches in the first few minutes of operation.

Keeping your chain sharp and lasting

A new chain at 7 dollars per chain is cheap. Replacing it every two weeks because of poor maintenance gets expensive fast. Three habits make a chain last:

Sharpen often, sharpen lightly

Touch up the cutters every time you refuel the saw. Two or three strokes with a round file — 5/32" for 3/8" LP chains, 7/32" for full 3/8" — keeps the chain cutting clean. A sharp chain throws large chips. A dull chain throws sawdust. If you see fine sawdust, sharpen.

Check oil flow

The bar needs oil to lubricate the chain. Hold the running saw with the bar tip a few inches above a clean stump or piece of cardboard and rev it briefly — you should see a faint spray of bar oil. If not, the oil port may be clogged — clean it with a small wire.

Rotate three chains, not one

This is why arborists buy 3-packs. One chain on the saw, one sharpened and ready, one in the truck. When the working chain dulls, swap it out and sharpen the dull one back at the shop. You never lose a working day waiting for sharpening.

Frequently asked questions

Bottom line

If you're running a Stihl saw and going through chains regularly, aftermarket 3-packs are the rational choice. The chains do the same job as Stihl® OEM at a fraction of the cost per cut. Confirm your spec (bar length, pitch, gauge, drive link count), buy three at a time, and rotate them through normal sharpening cycles.