Are All Stihl 3/8" .050 Chains Interchangeable?

[KCOLC]

A couple of questions wrapped into this post.

I just took a look at the Stihl chain chart. In particular 3/8" pitch chain. In the pitch column some chain is simply labeled 3/8" while other is 3/8" P. What is the difference?

In the chain "Type" column for each saw some of the 3/8" chain is PM3 (picco micro 3), PS3 (picco super 3) , RM3 (rapid micro 3), PMM3 (picco micro mini 3), and RS3 (rapid super 3) .

I'm assuming all of these chains are .050. Are they all interchangeable amoung Stihl saws that accept 3/8" chain?

Many thanks!

 

[lone wolf]

A couple of questions wrapped into this post.

I just took a look at the Stihl chain chart. In particular 3/8" pitch chain. In the pitch column some chain is simply labeled 3/8" while other is 3/8" P. What is the difference?

In the chain "Type" column for each saw some of the 3/8" chain is PM3 (picco micro 3), PS3 (picco super 3) , RM3 (rapid micro 3), PMM3 (picco micro mini 3), and RS3 (rapid super 3) .

I'm assuming all of these chains are .050. Are they all interchangeable amoung Stihl saws that accept 3/8" chain?

Many thanks!

No they are not all interchangeable. The 3/8 is for the med to larger saws like MS 440 and saws like that . The Picco Micro is for the 200T climbing saw and MS 241 for example there are many more. What saw you working on?

 

[ericm979]

3/8 low profile (Stihl calls it Pico, because being Stihl they need their own special word for it) is different from regular 3/8. You need a different sprocket and bar to run it. The chain itself is narrower than 3/8 and cuts a narrower kerf.

 

[Hundred Acre Wood]

Have a look at this chart:

https://www.stihlusa.com/WebContent/CMSFileLibrary/SawChainSelection-6.pdf
PMM3 is .043 gauge. "Regular" PIcco is .050 gauge

Also as mentioned previously, 3/8" LP (Picco) is not interchangeable with 3/8".

 

[KCOLC]

Eric & Hundred Acre, Thank you Thank You!

Looking for a lighter saw than my 262C-M that I can use the same chain with. The 262 uses 3/8"-.050-72. Want to run a 20" bar. Power isn't a huge factor for me. Just the length. A 20" bar saves the (my) back.

Thanks again

 

[Hundred Acre Wood]

The MS 26x series is the smallest Stihl professional saw that can use 3/8" and the 3003 bar mount. Anything smaller uses the 3005 bar mount and .325 or Picco chain and none of those have 20" bar options from Stihl. So you can neither use that bar with a smaller Stihl saw, nor get a 20" bar for a smaller saw from Stihl. Maybe a non-OEM option exists?

The 261 is a great saw. I would keep it, but I've got CAD just like everyone on these forums.

 

[Mad Professor]

The MS 26x series is the smallest Stihl professional saw that can use 3/8" and the 3003 bar mount. Anything smaller uses the 3005 bar mount and .325 or Picco chain and none of those have 20" bar options from Stihl. So you can neither use that bar with a smaller Stihl saw, nor get a 20" bar for a smaller saw from Stihl. Maybe a non-OEM option exists?

The 261 is a great saw. I would keep it, but I've got CAD just like everyone on these forums.

024

 

[Hundred Acre Wood]

024

True. I should have said "smallest current saw". I assumed the OP wanted a new saw since he currently has a 261c-m.

Nothing wrong with old saws. I have an 034 that I purchased new 30 years ago, still runs great!

 

[NoFair]

A couple of questions wrapped into this post.

I just took a look at the Stihl chain chart. In particular 3/8" pitch chain. In the pitch column some chain is simply labeled 3/8" while other is 3/8" P. What is the difference?

In the chain "Type" column for each saw some of the 3/8" chain is PM3 (picco micro 3), PS3 (picco super 3) , RM3 (rapid micro 3), PMM3 (picco micro mini 3), and RS3 (rapid super 3) .

I'm assuming all of these chains are .050. Are they all interchangeable amoung Stihl saws that accept 3/8" chain?

Many thanks!

They aren't all .050. Look at your bar and see what matches. 3/8p chains are for smaller saws, normal 3/8 is for 50+ cc saws

 

[ericm979]

Lots of companies make 3005 mount bars in 3/8. But manufacturers put narrower chain on smaller saws for a reason. 3/8LP is significantly narrower than 3/8. A small saw that normally runs 3/8LP will cut slower with 3/8.

 

[northmanlogging]

A couple of questions wrapped into this post.

I just took a look at the Stihl chain chart. In particular 3/8" pitch chain. In the pitch column some chain is simply labeled 3/8" while other is 3/8" P. What is the difference?

In the chain "Type" column for each saw some of the 3/8" chain is PM3 (picco micro 3), PS3 (picco super 3) , RM3 (rapid micro 3), PMM3 (picco micro mini 3), and RS3 (rapid super 3) .

I'm assuming all of these chains are .050. Are they all interchangeable amoung Stihl saws that accept 3/8" chain?

Many thanks!

technically the .050 gauge only covers the driver tooth thickness. the 3/8P for Pico isn't really 3/8 its closer to 9mm so it will run just fine in a .050 bar, but not on a true 3/8 sprocket nose or drive sprocket, which is super annoying.
For a chain to work with your saw, it has to match tooth/rail thickness as well as link pitch, otherwise "interesting" things happen. (interesting as lots of binding, likely so much as to not even go on said bar/saw and rather catastrophic clearance issues if you do somehow force the 3 together)

 

[benelli7d]

The MS 26x series is the smallest Stihl professional saw that can use 3/8" and the 3003 bar mount. Anything smaller uses the 3005 bar mount and .325 or Picco chain and none of those have 20" bar options from Stihl. So you can neither use that bar with a smaller Stihl saw, nor get a 20" bar for a smaller saw from Stihl. Maybe a non-OEM option exists?

The 261 is a great saw. I would keep it, but I've got CAD just like everyone on these forums.

CAD?

 

[Hundred Acre Wood]

CAD?

LMGTFY

https://www.arboristsite.com/threads/cad-explained.162192/

 

[benelli7d]

Thanks

 

[Mad Professor]

True. I should have said "smallest current saw". I assumed the OP wanted a new saw since he currently has a 261c-m.

Nothing wrong with old saws. I have an 034 that I purchased new 30 years ago, still runs great!

Almost all my Stihls are pre-limiter cap: 009, 020T,026 X 2, 028S, 036 X 2, 038s--->038M conversion, 038M, 056M, 066. All run like new with OEM Stihl parts. I have a bunch more in various stages of "going to fix": 026 X 2, 064, 056M. And parts carcasses for most of above

 

[Mad Professor]

technically the .050 gauge only covers the driver tooth thickness. the 3/8P for Pico isn't really 3/8 its closer to 9mm so it will run just fine in a .050 bar, but not on a true 3/8 sprocket nose or drive sprocket, which is super annoying.
For a chain to work with your saw, it has to match tooth/rail thickness as well as link pitch, otherwise "interesting" things happen. (interesting as lots of binding, likely so much as to not even go on said bar/saw and rather catastrophic clearance issues if you do somehow force the 3 together)

Drivers are 0.050 on 3/8 picco/lo pro. You can run picco on a 0.050 hard nose bar. Don't try it with a 3/8 sprocket tip bar or with a 3/8 drive sprocket.

Difference between 3/8 and 3/8 picco/lo pro is the chassis of the links. Pitch is the same.

This was beaten to death in the milling forum. I think the thread was "getting serious about lo pro"? by @mtngun

Here are two rims, a 3/8 7T and a 3/8 picco 7T (pin drive). Notice difference in diameters.

I had the picco rims made up (Danzco) with med drum spline to use on my 066 clutches

 

[Hundred Acre Wood]

To keep it simple for the OP I summarized it as "3/8" LP (Picco) is not interchangeable with 3/8". Because that answers his question about his bar. This thread was really resolved on post #5.

But for those who want to dive deeper into the rabbit hole... The pitch is not the source of the interoperability problem as some people seem to think. 3/8" and 3/8" LP (Picco) are both .375 pitch. The source of the interoperability problem is the drive link depth. 3/8" has a deeper drive link than 3/8" LP. Your post is a good visualization of how that chain design choice manifests itself in the resulting sprocket required.

An even clearer visualization can be found on this post:

https://www.arboristsite.com/threads/3-8-lo-pro-and-3-8-sprocket-differences.107256/post-1684778
The first photo shows the difference in driver links. The individual drive links in the bottom of that first photo show the 3/8" LP drive link on the left and the 3/8" drive link on the right (from some Carlton .058 chain).

The next two photos in that post show each chain on the opposite bar to visualize how the drive link depth interacts with the nose sprocket designed for the opposite chain's drive link depth.

 

[Mad Professor]

To keep it simple for the OP I summarized it as "3/8" LP (Picco) is not interchangeable with 3/8". Because that answers his question about his bar. This thread was really resolved on post #5.

But for those who want to dive deeper into the rabbit hole... The pitch is not the source of the interoperability problem as some people seem to think. 3/8" and 3/8" LP (Picco) are both .375 pitch. The source of the interoperability problem is the drive link depth. 3/8" has a deeper drive link than 3/8" LP. Your post is a good visualization of how that chain design choice manifests itself in the resulting sprocket required.

An even clearer visualization can be found on this post:

https://www.arboristsite.com/threads/3-8-lo-pro-and-3-8-sprocket-differences.107256/post-1684778
The first photo shows the difference in driver links. The individual drive links in the bottom of that first photo show the 3/8" LP drive link on the left and the 3/8" drive link on the right (from some Carlton .058 chain).

The next two photos in that post show each chain on the opposite bar to visualize how the drive link depth interacts with the nose sprocket designed for the opposite chain's drive link depth.

If you search through the "getting serious about lo pro" thread, there was pictures of 3/8 and 3/8 lo pro rims with each type chain showing how the different chassis made a mismatch.

It also showed the results of running the mismatch being peened out drivers.

I'm think those pictures may have been lost? Thread is pretty old.

 

[Hundred Acre Wood]

If you search through the "getting serious about lo pro" thread, there was pictures of 3/8 and 3/8 lo pro rims with each type chain showing how the different chassis made a mismatch.

Look again at my post above yours. As I went on to describe, that's exactly what that linked post shows.

 

[northmanlogging]

.365 vs .375, may not seem like much of a difference, but multiply that by 7 teeth, its .070" or >1/16" especially if you look at the nose sprocket what 15 teeth? and things tend to not line up very well, drive tooth length be damned. Cause if it was just a matter of tooth length then a pico chain would work just dandy in a standard 3/8 sprocket, but it don't.
And really the difference is doubled for every drive tooth, as the connecting links are also going to be .01" shorter...
As I said before its some metric number, 9.27mm or some such, why they don't just use .325 pitch I'll never really understand.