3/8" low profile narrow kerf, 1/4" are these all fads or do they really help smaller cc saws?

[ajc4]

When I bought my MS192 in 2014 or 2015 it came with a .043" guauge bar and Stihl's so-called picco micro mini (PMM) 3/8" pitch chain. I didn't notice until I went to buy a second chain that the cutters were norrower and smaller than regular 3/8" low profile chain. At the time, I recall Stihl listed this as the recommended chain for most of their smaller cc saws. I was noticing on Stihl's current bar & chain chart https://m.stihlusa.com/WebContent/C.../STIHL-Saw-Chain-Selection-Identification.pdf that they aren't using this as the OEM chain on anything anymore. Now the MS170 & MS180 uses 1/4" pitch, the MS193 and MS194 successors to my MS192 ship with standard pitch 3/8" low profile chain either Stihl PS or PM.

Before the proliferation of battery saws I haven't ever seen 1/4" chain. This seeds curiosity into a few questions that some on here might know:
1) Is there a nominal maximum power or maximum saw engine displacement for 1/4" vs 3/8 narrow low profile vs 3/8 low profile? (I don't see the first two standard on anything over about 35cc or battery powered stuff or the latter on anything over 45cc, so I guess the limit is in that neighborhood.)
2) Why did Stihl move away from the narrow kerf chain on the MS193? It's not a high torque saw. Wouldn't it work best with the smallest, sufficiently strong chain?
3) Do these really small 3/8" low profile narrow (PMM) and 1/4" chains really provide much benefit to compensate for shorter chain life and fewer sharpenings? Even if the kerf is narrower the wood fibers still have to be sliced on both sides of the cut. I'd speculate that a point of diminishing returns is reached for these really small chains.
4) Has anybody comparred these in timing tests 1/4" vs 3/8" narrow low profile vs 3/8" low profile vs 1/4" get some sense of the practical difference?

I didn't bring up .325" pitch vs .325" narrow kerf because nothing in my toolshed takes that pitch but the same questions apply here too.

 

[Bob Hedgecutter]

Plenty of small saws ran 1/4"chain back before 3/8LP was even invented- saws like the 020AV forerunner to your MS192.
Depends what you are cutting and where you are cutting it- but yes there are places for smaller finer chains, like beautification and repair pruning way up in a tree where you want fine neat cuts.
Some people can achieve a neater less damaging cut with fine sharp chains run on saws that what they can with a handsaw on small branch trimming close to the trunk.
Now if you are climbing a big old Fir and limbing it as a take down, falling the top out of it and chunking down the stem- something a bit more aggressive might suit your needs- where the finished cut is not so important.
If you are just a casual weekend saw user, doing too much research- it can get confusing with the plethora of choice there is out there, but for pro users and climbers- there is a horses for courses factor that comes into which chain suits which application better.

 

[full chizel]

The only saws using 1/4” here is the pole saws, MS 150/150T and battery saws. Everything else up to MS 250 is 3/8lp

 

[Del_]

I'm running 1/4 on my 241C.

 

[Franny K]

I'm running 1/4 on my 241C.

I will guess you are running 13RM not the mini stuff with 0.043 gauge drive links like I think post 1 is discussing.

Are you using an Oregon rim drive and 9 tooth or Stihl 8 tooth spur or something else?

 

[Pioneer]

A narrower cut equals less wood removed which equals less power required to make the same depth of cut. The downside is that the narrow cut leaves less margin for error before the bar starts binding.
Some videos show people experimenting with running low profile narrow kerf chains on high power saws, they do cut faster than normal chains, but in that type of application you run the risk of breaking the weaker links of the LP chains or throwing it because the drive teeth are not as deep in the bar.
Not an issue with smaller saws of course.
I recently talked with the owner of a Stihl dealership, his personal camp saw a Stihl 015 (Solo 600 copy?) had a .43 gauge PM chain on it. REALLY narrow kerf, and the 12" bar was so thin it was kind of floppy, but he said it cut very fast with the setup.

 

[Philbert]

1/4" is supplied on some of the battery saws, due to its low power demands. But honestly, I don't like sharpening it, and the small cutters have a short operating life.

3/8 low profile has been around a long time, is widely available, and there are even some 'PRO' versions of it a available. I like it

There is also.325 narrow kerf chain, which is OEM on several Husqvarna saws, and available from Oregon and Carlton as well. I have had good experience with that chain too.

Philbert

 

[Pioneer]

I can personally vouch for the Stihl 23 RS Pro full chisel narrow kerf .325 chain, it cuts very fast.

 

[Franny K]

I was noticing on Stihl's current bar & chain chart https://m.stihlusa.com/WebContent/C.../STIHL-Saw-Chain-Selection-Identification.pdf that they aren't using this as the OEM chain on anything anymore. Now the MS170 & MS180 uses 1/4" pitch, the MS193 and MS194 successors to my MS192 ship with standard pitch 3/8" low profile chain either Stihl PS or PM.

That page you linked has problems. Look at the top line first box says 1/4 pitch but look at the Rec chain loop marketing it calls out 61pmm3 which is the 3/8 extended 1.1mm drive link thickness. The drive link count and the nose sprocket teeth match with 61pmm3 not 1/4 inch stuff. I picked up a ms150 and it had baby 1/4 inch pitch chain which would start with a 7 in the coding.

I also note the chain that starts with 7 is called extended so it probably does not fit well on the sprockets for chain that starts with 1 or in Oregon 25. The 0.050" or 1.3mm gauge stuff.

 

[RED-85-Z51]

I converted a customers ms180c to 3/8LP .050ga bar and chain. He's used it for years with a 16 inch picco micro .043 setup for years and complained about how often he had to go to the dealer for new chains due to stretch.

I set him up with some Oregon loops and Oregon bar...so far he says its needing to be snugged up about half as often and he says it seems to cut straighter...albeit his old bar was worn.

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[Bob Hedgecutter]

He's used it for years with a 16 inch picco micro .043 setup for years and complained about how often he had to go to the dealer for new chains due to stretch.
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I would put that down to operator error before blaming the chain for stretching.

 

[windthrown]

I put 3/8 lopro Picco B&C full chisel non safety on my 026 saws and they run like a dream. Way better than 3/8 std or .325. I also run that on my 211, 020 and my 180c saws.

 

[RED-85-Z51]

I would put that down to operator error before blaming the chain for stretching.

My personal experience with the thin stuff isnt much different. .050 gauge seems to last longer than .043 as far as lifespan between new and needing shortened and between snug downs. Same with .043 1/4" and .043 3/8LP...the small stuff, while it has less drag in the cut and bar, isnt as robust as the 3/8lp.

12" bar...the quarter inch chain has 20 more drive links and more rivets..more stretch.

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[Bob Hedgecutter]

My personal experience with the thin stuff isnt much different. .050 gauge seems to last longer than .043 as far as lifespan between new and needing shortened and between snug downs. Same with .043 1/4" and .043 3/8LP...the small stuff, while it has less drag in the cut and bar, isnt as robust as the 3/8lp.

12" bar...the quarter inch chain has 20 more drive links and more rivets..more stretch.

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You forgot to factor in quality of the chain and the ability of a user to over tension, keep running a dull chain, fail to clean out oil galleries in the bar...........

 

[RED-85-Z51]

Dealer told him they (stihl dealers) were the only place that could get the right chain for the saw...so He has only run stihl chain up to this point and the tensioner is the stupid roller wheel type...not known for over tensioning.

He's one of those people that buys briggs brand oil for his mower...stihl brand oil for his saw, buys tires exactly like what came on his truck from the dealer.

We'll see...all other things being equal, how he likes the bar and chain long term. Ill dig the old bar up...the roller tip was smooth as glass but the bar was as worn as ive seen one...a good 15 years of use probably.

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[1289]

3/8 p .043 "mini" tooth chain
3/8 p .050

.050 picco is more suitable for me for forestry work, firewood / thinning / felling, softwood. 30 up to 50cc, the chain is much cheaper too.

 

[ajc4]

Plenty of small saws ran 1/4"chain back before 3/8LP was even invented- saws like the 020AV forerunner to your MS192.
Depends what you are cutting and where you are cutting it- but yes there are places for smaller finer chains, like beautification and repair pruning way up in a tree where you want fine neat cuts.
Some people can achieve a neater less damaging cut with fine sharp chains run on saws that what they can with a handsaw on small branch trimming close to the trunk.
Now if you are climbing a big old Fir and limbing it as a take down, falling the top out of it and chunking down the stem- something a bit more aggressive might suit your needs- where the finished cut is not so important.
If you are just a casual weekend saw user, doing too much research- it can get confusing with the plethora of choice there is out there, but for pro users and climbers- there is a horses for courses factor that comes into which chain suits which application better.

I am a casual weekend user and I do have too much time on my hands lately. I'm not looking for delicate cuts. I'm running homeowner class saws for regular homeowner stuff - firewood and trimming limbs. I know there are better saws out there, but casual trimming & firewood use isn't worth what a pro saw costs. So, really, I just want the saws I can justify affording setup as well as they can be. I always assumed that whatever the saw ships with must be pretty close the best for typical uses (and my use is pretty typical). I mean, Sthil should know more about how to setup a saw than me, right? What threw me is that the chart of the current Stihl models seemed to be different than published in the past. If Stihl is confused about the best way to setup a saw then I don't feel quite so bad that I am too. On the otherhand, Franny K points out that the 1/4" label in the updated Stihl chart I linked in the original post appears to be a mis-print. The bar sizes and number of drivers for the MS170 and MS180 are consistent with 3/8", not the 1/4" printed in the left column. Though they do show regular kerf 3/8" LP/PM3 chain for the MS193 & 194. I'm positive they used to call out PMM3 for the MS192. Even though that's less durable, the MS192 is no powerhouse by any stretch.

For what its worth I've always stayed with the semi-chisel PMM3 safety chain on the MS192t. More "safety" seems like a good idea on a tophandle than less and I'm still pretty careful where I point the tip of that thing. I don't climb but I like a tophandle for prunning and small cuts. Actually what I really liked is the old Homelite Super 2 that had a top throttle trigger AND a back throttle trigger. It could tophandle when I wanted to tophandle and it could back handle when I wanted to backhandle. They don't make them like they used to, I guess. My 025 is setup for PS chisel for firewood. I got that used without a bar and opted for the 3/8" LP/PS, 6-tooth setup instead of .325 hoping that would help the smallish cc engine out a bit bucking big pieces (or, big for an 025). It does seem to handle 18" bar-length cuts reasonably okay enough that I don't see any need for anything bigger, heavier or more expensive. In any case I'm content with how the two setups handle thier intended role but I don't really have any other experience to compare to.

 

[Chris-PA]

Stihl is not the only 0.043" lo pro out there - I've used Oregon 90 for years on my Husky 142 with a 16" bar. It's not ported, but with a muffler mod it's plenty strong. I've never had any stretching or reliability issues with that chain, and it cuts very fast. The cutters on 90 are quite a bit taller than 91, not just narrower.

Carlton 0.043" is a waste - the cutters are identical to the 0.050" lo pro so there is no reduced load on the saw, the kerf is just 0.007" narrower.

 

[Philbert]

I have Oregon Type 90 on my 40 Volt pole saw. Works well. They recommend a slightly larger file for it (4.5 mm, or 11/64"), which is a bit harder to find, than for Oregon Type 90 chain (4.0 mm, or 5/32").

Philbert