Stihl Chainsaw File Size Chart: 5/32, 3/16, 13/64, 7/32

A Stihl chain’s file size depends on its pitch, not the saw model. Read the code embossed on the depth gauge: 1 and 6 take a 4.0 mm (5/32″) file, 2 takes 4.8 mm (3/16″), 3 takes 5.2 mm (13/64″), 4 takes 5.5 mm (7/32″). One catch: the same saw can ship with two different pitches, so check the chain itself before you buy a file.

Which File Does a Stihl Chain Take? Start With the Depth Gauge Code

Stihl embosses a small code in the area of the depth gauge on every cutter. That code tells you the chain pitch, and the pitch decides the round file diameter. We cross-checked this against four STIHL owner’s manuals (MS 170/180, MS 171/181/211, MS 210/230/250 and MS 271/291) and STIHL’s own sharpening guides, so the numbers below come from Stihl, not from forum memory.

1. Find a cutter: Look at the small hook-shaped depth gauge just ahead of any cutting tooth.
2. Read the code: Look for a single digit or letter embossed near it (1, 2, 3, 4, 6, 7, or P).
3. Match it to the chart: The table below turns that code into a file diameter.

Matching File Size To Chain Specs

Only pitch matters for file choice. Pitch is the cutter spacing, and a bigger pitch means a bigger cutter that needs a bigger round file. Drive link gauge (1.1, 1.3 or 1.6 mm in the Stihl manuals) only decides whether the chain fits your bar groove, so a drive link mismatch will not change your file. Pitch and gauge are separate measurements.

Using the Stihl File Size Chart

Depth gauge code	Chain pitch	Round file (mm)	Round file (inches)
7	1/4″ P (Picco)	3.2 mm	1/8″
1	1/4″	4.0 mm	5/32″
6, P or PM	3/8″ P (Picco)	4.0 mm	5/32″
2 (or 325)	.325″	4.8 mm	3/16″
3	3/8″	5.2 mm	13/64″
4 (or 404)	.404″	5.5 mm	7/32″

The 3/8 trap: 3/8″ P (Picco) and full-size 3/8″ are the same 9.32 mm pitch, but Stihl lists them with different files, 4.0 mm for the Picco and 5.2 mm for the standard chain. So “3/8 chain” is not one file size. The code tells them apart: 6, P or PM is Picco, 3 is standard. A 5.2 mm file is too big for a Picco chain and a 4.0 mm file is too small for a standard one.

Stihl lists six file diameters, from 3.2 mm to 5.5 mm, one per pitch. Source: STIHL chainsaw sharpening guide

Alternative Methods for Determining File Size

If the code has worn off, read the chain designation instead. Stihl’s manuals list chains such as 63 PM3, 26 RM3 and 36 RM3, and the number in front follows the pitch in every list we checked: 61 and 63 are 3/8″ P, 23 and 26 are .325″, 36 is 3/8″. The same designation is printed on the chain packaging and in your owner’s manual. If you have none of these, a Stihl dealer can read the pitch off the chain in seconds.

Chain designation prefix	Pitch (per Stihl manuals)	Round file
61, 63 (e.g. 63 PM3)	3/8″ P	4.0 mm (5/32″)
23, 26 (e.g. 26 RM3)	.325″	4.8 mm (3/16″)
36 (e.g. 36 RM3)	3/8″	5.2 mm (13/64″)

Chainsaw File Sizes: Complete Reference Table

Here is the same Stihl data arranged by chain pitch, with the Stihl chain types the manuals list for each pitch. Use it when you know your pitch but not the code.

Chain Pitch	File Diameter	File Size (inches)	Stihl chain types from the manuals
1/4″ P	3.2 mm	1/8″	Not listed for the saws below
1/4″	4.0 mm	5/32″	Not listed for the saws below
3/8″ P (Picco)	4.0 mm	5/32″	61 PMMC3, 63 PMC3, 63 PM3, 63 PD3, 63 PS3
.325″	4.8 mm	3/16″	23 RM3, 23 RS, 26 RM, 26 RM3, 26 RS
3/8″	5.2 mm	13/64″	36 RM3, 36 RS3, 36 RD3
.404″	5.5 mm	7/32″	Not listed for the saws below

The file diameters come from the sharpening-tools table in the STIHL MS 210/230/250 manual. Running a non-Stihl chain? Our pitch-to-file chart for any brand covers it, and our best chainsaw files roundup shows which packs actually contain each diameter. For how the two common pitches differ in use, see our .325 vs 3/8 chain comparison.

File Size by Stihl Model: What the Owner’s Manuals List

People search by saw model, and that is where most wrong-file purchases start. Here is what Stihl’s own manuals list for the cutting attachments of five popular saws.

Stihl saw	Chain pitch in the manual	Round file needed
MS 170, MS 180	3/8″ P only	4.0 mm (5/32″)
MS 211	3/8″ P only	4.0 mm (5/32″)
MS 250	3/8″ P or .325″	4.0 mm (5/32″) or 4.8 mm (3/16″)
MS 271 (Farm Boss)	.325″	4.8 mm (3/16″)
MS 291	.325″ or 3/8″	4.8 mm (3/16″) or 5.2 mm (13/64″)

The corrected myth: a saw model does not fix your file size. The MS 250 manual lists both a 3/8″ P chain on 30 to 45 cm bars and a .325″ chain on 35 to 45 cm bars, and the MS 250 page on STIHL USA currently shows an 18″ bar with a .325″ RM3 chain. Two owners of the same saw can need different files, and chains get swapped over the years, so trust the code on your chain, not the model number. Not sure which saw suits you? Our MS 170 vs 251 vs 271 comparison covers the differences, and our Stihl carburetor settings guide is built the same manual-first way.

The Role Of File Size In Sharpening

The round file sets the cutting edge, and with the right file holder it also produces the correct side plate angle. Stihl’s manual says that angle results automatically only when the specified file holder and file diameter are used, so a wrong diameter breaks that link. Stihl also warns that uneven angles make the chain run roughly, wear quickly and can lead to chain breakage.

Tooth shape (Stihl)	Examples	Filing angle	Side plate angle
Micro (semi-chisel)	63 PM3, 26 RM3, 36 RM	30°	75°
Super (full chisel)	63 PS3, 26 RS, 36 RS3	30°	60°
Ripping chain (X in name)	63 PMX, 36 RMX	10°	75°

“STIHL saw chains are sharpened with a 30° sharpening angle.”

STIHL MS 210/230/250 instruction manual

Filing Steps and Safety Checks for Stihl Chains

This is the short version; our full Stihl chain sharpening guide covers technique in depth. Start with the safety points Stihl lists:

• Wear gloves made of a resistant material, such as leather (STIHL manual and STIHL sharpening guide).
• Make sure the chain is stopped and the chain brake is engaged. Stihl’s manual says to block the chain by pushing the hand guard forward.
• Secure the saw first. The manual says to clamp the guide bar if necessary.

1. Clean the chain and check it: Look for cracks and damaged rivets, and tension the chain a little so the teeth sharpen more effectively.
2. Choose the file by pitch: Use the diameter from the chart above, and use a file holder, because the holder carries the angle markings.
3. Hold the file level: Keep it horizontal, at 90° to the side of the guide bar, with a quarter of the file diameter above the top of the tooth.
4. File forward only: The file cuts on the forward stroke only; lift it on the backstroke, and file from the inside outward.
5. Go light: Stihl says to sharpen frequently, removing little material. Two or three strokes per cutter usually do for a simple touch-up.
6. Match the cutters: Every cutter must end up the same length as the shortest one.

Then check the depth gauges. Lay the file gauge for your pitch on the chain: if a depth gauge sticks up past the gauge, Stihl says to file it flush with a flat saw chain file. Stihl’s manual warns that depth gauges set too low raise the chain’s kickback tendency.

Chain pitch	Depth gauge distance (mm)	Depth gauge distance (inches)
1/4″ P	0.45	0.018
1/4″	0.65	0.026
3/8″ P	0.65	0.026
.325″	0.65	0.026
3/8″	0.65	0.026
.404″	0.80	0.031

Those are the distances in Stihl’s MS 250 manual. For softwood outside the frost season, the same manual allows up to 0.2 mm (0.008″) more.

Signs Your Stihl Chain Is Dull

STIHL’s sharpening guide lists five signs that a chain needs filing:

• The chain does not pull itself into the wood.
• It makes fine sawdust instead of coarse chips.
• It smokes even though the lubrication is working.
• The saw pulls to one side and cuts crooked.
• The saw chatters and bounces.

If you see these and the chain is already sharp, wrong angles or too-low depth gauges are the usual suspects, and a wrong file diameter is one way to get there.

Keep reading

• What Size File for a Ryobi Chainsaw? Match the Chain Pitch
• Walmart Chainsaw Chains: Sizes, Fit & Cross-Reference Guide
• 28-Inch Chainsaw Bar: What CC You Need (Compatibility Chart)

Stihl Chainsaw File Size Faqs

How do I know what file to use on my Stihl chainsaw?

Look for the small code embossed in the depth gauge area of a cutter, then match it to Stihl’s chart: 1 and 6 take a 4.0 mm (5/32″) file, 2 takes 4.8 mm (3/16″), 3 takes 5.2 mm (13/64″), 4 takes 5.5 mm (7/32″) and 7 takes 3.2 mm (1/8″). If the code is worn, read the chain designation (such as 26 RM3) from the packaging or your owner’s manual.

What size file does a Stihl MS 250 use?

It depends on the chain. Stihl’s MS 250 manual lists a 3/8″ P chain (63 PM3, 4.0 mm or 5/32″ file) and a .325″ chain (26 RM or 26 RM3, 4.8 mm or 3/16″ file). Check the code on your own chain, because the same model can carry either one.

What size file do I use for 3/8 chain?

It depends which 3/8. Stihl lists 3/8″ P (Picco) chain at 4.0 mm (5/32″) and full-size 3/8″ chain at 5.2 mm (13/64″). Both are 9.32 mm pitch. The depth gauge code separates them: 6, P or PM is Picco, and 3 is standard.

What size file do I use on a.325 chain?

A .325″ pitch Stihl chain takes a 4.8 mm (3/16″) round file. Stihl’s manuals list .325″ chain on the MS 250, MS 271 and MS 291, and the depth gauge code is 2.

What file size do Stihl MS 170, MS 180 and MS 211 chains take?

Stihl’s manuals list only 3/8″ P chain for these saws, so the round file is 4.0 mm (5/32″). Check your own chain if it was replaced with a different type.

Can I use a file that is slightly bigger or smaller?

Use the diameter Stihl lists for your pitch. Stihl’s manual says the correct side plate angle results automatically only when the specified file holder and file diameter are used, so a different diameter changes the result.