Well since I`m the buffoon who found this gem, I have taken literary license to edit out most of the more lucid and informed replies and have thus condensed the remainder of the thread down to the parts that I found funniest or most misguided. I`d like to reply to the thread, but alas, I have been banned since I have nothing of value to offer over there.
Here it is, enjoy!
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chainsaw chain pitch question?
Posted by runlong (My Page) on Mon, Jan 19, 04 at 10:20
I am looking at purchasing a second "larger" saw. The saw I am considering comes with a 24" bar
(used). The chain pitch/gauge is .375/.050. I would be looking to get a smaller bar for this saw.
The manufacturer lists different bar/chains with pitches of 3/8, .325, and .375. Some of the .325
and .375 bars are listed for the saw I might purchase. Since the saw already has a .375 bar/chain
I would assume that I would need to stick with that pitch or else change the sprocket. My
question is, what is the difference between a 3/8 pitch chain and a .375 pitch chain since 3/8
=.375?
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RE: chainsaw chain pitch question?
Posted by: ShellBark va (My Page) on Mon, Jan 19, 04 at 16:10
i think metric measurements is the only difference.The .375 sounds more metric than 3/8.Keep in
mind to that your chain pitch will have to match the bar pitch,if your usin a sprocket nose bar.
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RE: chainsaw chain pitch question?
Posted by: BillW 5b (My Page) on Mon, Jan 19, 04 at 19:50
Your choice is limited by the power of your saw.
.375 is just 3/8 lo-profile chain and is used on saws with less than 2.5 cu. in.
To be able to use .325 chain, you need a motor with at least 2.5 cu. in.
You will find that the drive sprockets available from either OREGON or the saws Mfgr will also
limit your choice.
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RE: chainsaw chain pitch question?
Posted by: KarlP (My Page) on Mon, Jan 19, 04 at 21:15
3/8 chain is the same as .375
3/8 low-profile chain is .370
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RE: chainsaw chain pitch question?
Posted by: sorethumbs NW WI (My Page) on Tue, Jan 20, 04 at 10:58
My saw is running a 3/8" low-profile chain. My oregon manual says nothing about an actual .370
pitch for a 3/8" LP chain. I'm confused by this. Is a 3/8-LP chain compatible/interchangeable
with other, not lo-profile, 3/8" chain?
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RE: chainsaw chain pitch question?
Posted by: hokiebob1 va (My Page) on Tue, Jan 20, 04 at 12:03
I'm confused. Isn't the pitch simply the distance between every third rivet?? If so, 3/8LP would
definitely fit on any .375" saw, since .375 is 3/8" anywhere you go. I've not seen any
specification anywhere referring to 0.370", though I should state that I'm a novice compared with
most on this forum.
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RE: chainsaw chain pitch question?
Posted by: LesTWV z6WV (My Page) on Tue, Jan 20, 04 at 14:38
Bob
You are confused because you are being misinformed.
Here in the US we use both Fractional and Decimal system.
Decimal .375 is equal to the fractional number 3/8".
Just take 1 divide it by 8 then multiply that number by 3 and you will see that .375" is equal to
3/8" just as Yourself and Runlong already knew.
This number has no bearing to "Low profile" chains nor anything else other than the pitch of the
drive sprocket.
Look at the pic below.
Chain pitch is determined by measuring the distance between the top of the chains guides and
dividing that number by 2. Pointed out here as A. If you were to take a .375, 3/8 chain and shave
.005 off of the distance between the guides. That will not give you a low profile chain.
What a chain "is" all has to do with the Drags in relation to the cutting teeth as pointed out
here as B . The combo used here will determine if the chain is a Low Profile, Chipper, Low
Kickback, Ripper or a Billy Mayse Orange peeler Special..
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RE: chainsaw chain pitch question?
Posted by: sorethumbs NW WI (My Page) on Tue, Jan 20, 04 at 16:49
sooooo........ will a 3/8" (.375) pitch chain work on a bar/sprocket currently set-up to run a
3/8" LOW PROFILE chain?
Now I'm even more confused as my Oregon manual tells me:
"chain pitch is the distance between any three consecutive rivits, divided by two." To me this
means "B" in Les's picture. "A", the distance between the drive links, is not even mentioned in
my manual. However, just eyeballing the two, they look to be almost identical.
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RE: chainsaw chain pitch question?
Posted by: fred129 Z3 NC (My Page) on Tue, Jan 20, 04 at 16:49
well i aint gonna say sure .. but i do know low pro dont fit standardard 3/8 sometimes . not rite
any way.. course i could always be wrong. but its never happened before..
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RE: chainsaw chain pitch question?
Posted by: hokiebob1 va (My Page) on Tue, Jan 20, 04 at 16:50
Thanks, but I thought thats what I said-a 3/8's chain is the same as a .375" chain, which is the
distance between every third rivet (I forgot to divide it by two). This designation only has to
do with the drive side if you will, of the chain, not the cutting side. Is this right?
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RE: chainsaw chain pitch question?
Posted by: LesTWV z6WV (My Page) on Tue, Jan 20, 04 at 17:50
All of the below chains are 3/8" and made by Oregon.
If you notice. The design of the cutting teeth and drags along with their height are differant
and that is what makes a chain what it is. The pitch number has no bearing on what type of chain
you are using.
Low Profile
Micro Lite
Ripper
Sorethumbs
If you look. The distance between any three consecutive rivits is the same as it would be if you
were to measure the distance between the top of the guides.
Fred
You say, "I do know low pro dont fit standardard 3/8" sometimes". Yes it will. BUT, The saw
manufactor may call for you to use a Low Profile chain. This is mainly due to the cutting teeth
sticking above the bar so far due to the thickness of the plate that they may hit and damage
something on the saw.
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RE: chainsaw chain pitch question?
Posted by: KarlP (My Page) on Tue, Jan 20, 04 at 20:28
Maybe I'm wrong. Enlighten me.
If not low-profile, what is the ".370" chain that many online dealers sell?
If the drive links are the same length why do you need a different drive sprocket for low profile
chain if it really is .375? I've read in the yahoo milling group that running 3/8" low profile on
a standard 3/8" drive sprocket will greatly increase your chances of breaking the chain. Stihl
must sell separate low-profile drive sprockets for a reason. No?
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RE: chainsaw chain pitch question?
Posted by: ricksvar 6 (My Page) on Wed, Jan 21, 04 at 7:21
Well I'am probably wrong,but a 3/8 sprocket for low profile chain like Stihl PM and a 3/8
sprocket for say Stihl RS chain are going to be different.While spacing is the same,chain
guides(drivers)are smaller on the low profile and larger on RS.Note the image above.Also if you
have a bar with roller tip it should match the pitch and size of the drivers.RRRRRrrrrrr,does
this make sence?
Rick
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RE: chainsaw chain pitch question?
Posted by: sandbur 6/7 (My Page) on Wed, Jan 21, 04 at 10:35
And I have always thought the plumbing industry was the most screwed up industry on earth. Now
I'm beginning to re-consider.
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