.325 or .375 debate!

[DanTheCanadian]

So I've been arguing I mean debating with my father in-law for awhile now on whether or not it would be worth throwing a .325 chain on my 455 rancher.

I know that this topic has been beat to death but instead of gleaming the info that is in there somewhere between all the BS I figured I could ask again.

The rancher is running a 20" 3/8 and he says that it would benefit from a .325 and an 18" bar. I agree that obviously a 18" will pull easier but for the sake of arguement if I put a .325 with a 20" bar would I actually see a difference? I like how it runs now with the the B/S I have on it so it isn't a question of not being happy with it.

I'm not looking to turn it into a high output saw because for most my cutting I'm using either the 372xp or the dolmar 7310. The rancher is the trail cutter and small firewood feller.

So to sum, .325 or .375. And.... Go!

 

[old-cat]

My first STIHL was an MS 290, same situation, 20" bar 3/8 chain. I got a 20" bar with .325 chain 7 t drive and it cut noticeably faster.

 

[1Cut]

I have worked on a few of the 455 ranchers most have had .375. A couple have had .325 I honestly don't really notice much difference… not enough to justify the cost anyway. Obviously a 18" will give the saw "more power" just because it has less chain to pull. My opinion.. Others may disagree.

 

[DanTheCanadian]

That was about my opinion also 1cut bit I've been known to be wrong

 

[sunfish]

.325 chain on a 20" bar would cut faster. But that saw has enough power to pull 3/8 chain OK.

 

[Topbuilder]

My 455R handles the 3/8 fine. I like the 7/32 file. I just bought a 24" Power Match with a skip chain. Handles it fine. Little jumpy. It will have to work 'till I can swing a 390XP (Woods ported).

 

[Chris-PA]

Wouldn't it be more a matter of the chain rather than the pitch? I have 0.325" Oregon 20BPX on one of my saws, and it is pretty much the same cutter height and kerf width as typical 3/8. The 0.325" has 11% more cutters per length, so why wouldn't it be a higher load on the saw?

Of course, you can get 0.325" chain that is narrower kerf too.

 

[DanTheCanadian]

I was under the Impression that the .325 takes less "bite" then a 3/8 which would explain why a Walmart poulan doesn't come with a .404 chain.

 

[sunfish]

I was under the Impression that the .325 takes less "bite" then a 3/8 which would explain why a Walmart poulan doesn't come with a .404 chain.

Yes, takes less power to pull .325. But there is more to it than just that, chain speed with rim size, etc...

 

[SawTroll]

I was under the Impression that the .325 takes less "bite" then a 3/8 which would explain why a Walmart poulan doesn't come with a .404 chain.

That's marginal, and sometimes not at all - and there are more cutters in the wood with .325 (again marginal). The "bite" depends on the raker setting, that normally is the same on both pitches.

The main differense is that a .325x7 sprocket is smaller than a 3/8"x7 one, which means that the saw will put more torque on the chain. It also will run a little smoother, because of the reduced distanse between the cutters.

 

[sunfish]

That's marginal, and sometimes not at all - and there are more cutters in the wood with .325 (again marginal). The "bite" depends on the raker setting, that normally is the same on both pitches.

The main differense is that a .325 sprocket is smaller than a 3/8"x7 one, which means that the saw will put more torque on the chain. It also will run a little smoother, because of the reduced distanse between the cutters.

A much better explanation than I wrote. Good stuff!

 

[DanTheCanadian]

Wow sawtroll that was an excellent explanation. It makes a lot more sense now. Out of curiosity how would a .325x8 stack against a .375x7. I might be getting in dangerous territory here.

 

[SawTroll]

Yes, takes less power to pull .325. But there is more to it than just that, chain speed with rim size, etc...

What I wrote translates into what you wrote.

 

[SawTroll]

Wow sawtroll that was an excellent explanation. It makes a lot more sense now. Out of curiosity how would a .325x8 stack against a .375x7. I might be getting in dangerous territory here.

Then the torque advantage disappears, and we are down to the details of the individual chain. The differense in effective torque from a given powerhead will be minimal.

...and don't do any maths on the .375 number, as the actual pitch of 3/8" chain is more like .366....

 

[old-cat]

What 1cut said is true, The cost don't justify the switch. The best way to make 20" x 3/8 cut is to get a pro 60cc saw!

 

[Homelite410]

I don't go to the woods with less than 60cc 20" so for me .325 is pointless. I also do not like the chip clearance under the tail of .325, 3/8 seem to pull chips better l from my perspective anyway.

 

[sunfish]

I don't go to the woods with less than 60cc 20" so for me .325 is pointless. I also do not like the chip clearance under the tail of .325, 3/8 seem to pull chips better l from my perspective anyway.

But if like a lot of us that go to the woods with 45-50cc 16-20", .325 makes good sense.

 

[Chris-PA]

That's marginal, and sometimes not at all - and there are more cutters in the wood with .325 (again marginal). The "bite" depends on the raker setting, that normally is the same on both pitches.

The main differense is that a .325x7 sprocket is smaller than a 3/8"x7 one, which means that the saw will put more torque on the chain. It also will run a little smoother, because of the reduced distanse between the cutters.

I don't think that quite works though. In comparing a 0.325"x7 sprocket is smaller than a 3/8x7, the circumference will need to be 11% smaller. That equates to a diameter that is 3.5% smaller. So if the cutters were the same, the load with 0.325" would go up by 11%, but the diameter (gear ratio) would only go down by 3.5%. So 0.325" chain would present more load to the saw.

Diameter = Circumference/PI

I think it's all about cutter profile.

 

[DanTheCanadian]

Okay, so if the "ease of pull" for lack of a better term is only marginally reduced by the smaller cutters then why do the small CC saws come with the small chain. There must be a reason besides thread fodder.

 

[DanTheCanadian]

I don't go to the woods with less than 60cc 20" so for me .325 is pointless. I also do not like the chip clearance under the tail of .325, 3/8 seem to pull chips better l from my perspective anyway.

And I use a 394xp for fence posts. Sorry I thought this was a pissing contest. I myself won't go without a second saw and all my other saws are 70cc and up so I agree completely. My experience is on par with yours though about chip clearance. My father in-law has a shidaiwa 488 with .325 and it seems to not clean as well.