The Forestry Forum

General Forestry => Chainsaws => Topic started by: Tim/South on December 20, 2009, 10:24:04 PM

Title: Understanding Chain Pitch
Post by: Tim/South on December 20, 2009, 10:24:04 PM
I need some insight on understanding chain pitch and some other terms.

Here is the situation.
I have three Husky saws. An older 50, a 353 and an old 272.
The 272 finally gave up the ghost. I had just bought a new 24" bar and a couple of chains for it. The bar and chains are 50 ga. I have come across a 372 I will probably end up buying.
My brother gave me a Shindaiwa 757 in nearly new condition. The 757 has a 58 ga. bar and chain. I have really been impressed with this saw.

I am considering buying a spool of chain and would like to run the same chain on the 353, a 372 and the 757.
If I buy a 50 ga bar for the Shindaiwa will I need to change sprockets as well? I have no idea if the drive sprockets are the same from brand to brand.

When a chain is listed as 3/8's pitch, .325 or .404 pitch, what is that referring to?
I have been told it is the drive teeth, the cutting tooth pitch and the width.
I need to have a better understanding of the term "pitch" so I can get it in my head what may work and what will not.

Thanks for any insight/education on this./
Title: Re: Understanding Chain Pitch
Post by: nmurph on December 20, 2009, 10:30:57 PM
you are confusing pitch and gauge.

pitch... the distance bw any three rivits divided by two.  i.e.  1/4", .325, 3/8". .404

gauge....the width of the drive link   .43, .50, .58, .63

chains can come in many, but not all combinations of the above. add to this low-profile (lo-pro) and narrow-kerf (NK0 and things get very confusing.... the most common are .325/50, .325/58 or .325/63
and 3/8"/.50, 3/8"/.58, or 3/8".63. some larger saws use .404, which is .63.
Title: Re: Understanding Chain Pitch
Post by: Tim/South on December 20, 2009, 11:43:19 PM
Is the term pitch referring to the cutting teeth or the drive part?
I was told if I changed chains that I would also need to change drive sprockets.
Will a .325 pitch chain have the same drive sprocket as a 3/8?
Title: Re: Understanding Chain Pitch
Post by: gemniii on December 21, 2009, 12:22:32 AM
go to Madsen's http://www.madsens1.com/
Bailey's http://www.baileysonline.com/default.asp O
Oregon http://www.oregonchain.com/index_f.htm

They all have more great info and pics
Title: Re: Understanding Chain Pitch
Post by: mike_van on December 21, 2009, 06:21:32 AM
Don't buy a spool of chain without the 100.00+ tools to break & re-spin the rivets.  You need to use a LOT of chain, or sell to others to make this pay. 
Title: Re: Understanding Chain Pitch
Post by: Gary_C on December 21, 2009, 10:28:19 AM
Mike is right. I use a lot of chain and even have the tools to make my own loops, but I can buy premade loops cheaper than I can make them.  So let someones else take the time to count links and just order premade loops from Bailey's.
Title: Re: Understanding Chain Pitch
Post by: rebocardo on December 21, 2009, 07:05:00 PM
For cost and interchange I run 3/8 x .50 on all my saws except the smaller Sthil and polesaws. Which covers 18-32".
Title: Re: Understanding Chain Pitch
Post by: simonmeridew on December 21, 2009, 10:47:15 PM
Tim
to answer your question about whether .325 is the same as 3/8, answer is no. If you have a .325  sprocket with 8 drive, (it's clearly embossed on the sprocket disc) and try to use it with a 3/8 -   7 chain, it'll hook up ok on the bar and sprocket, but when you roll the chain around the bar by hand, you'll hear a "click" every time the sprocket goes around; don't try to use it.
simonmeridew
Title: Re: Understanding Chain Pitch
Post by: Rocky_J on December 21, 2009, 11:04:44 PM
The pitch is the distance between the drive teeth on the chain and the spacing of the spurs on the sprocket. Different pitch chains are not interchangeable. The three common chain pitch sizes are 3/8" lo-pro, .325 and 3/8. In order to differentiate between lo-pro and full size 3/8, Bailey's and some other retailers may sometimes refer to them as .365 and .375 (although that isn't technically correct). It can make communication easier though.

Gauge is the thickness of the drive teeth on the bottom of the chain, and the width of the groove in the bar. There are three common gauges and the chain gauge must match the bar gauge. The gauge will be .050, .058 or .063. Sprockets are not sized for gauge, only pitch.
Title: Re: Understanding Chain Pitch
Post by: Tim/South on December 22, 2009, 12:45:17 AM
Thanks for the replies and advice. I have a pretty good understanding of it now.
A young guy at the front desk of a local saw shop kind of confused me some. I needed some clarification.

I already have a pretty large assortment of chain saw tools. Breaking and spinning is not a problem. I usually keep several chains for each saw. I refuse to cut with a dull chain.
The addition of the Shindaiwa caused a need to understand the difference in pitch.

Thanks Again for the help.
Title: Re: Understanding Chain Pitch
Post by: mike_van on December 22, 2009, 06:18:24 AM
Quote from: Tim/South on December 22, 2009, 12:45:17 AM


I already have a pretty large assortment of chain saw tools. Breaking and spinning is not a problem. I usually keep several chains for each saw. I refuse to cut with a dull chain.




You could just sharpen the chain rather than make a new one?   :D :D :D
Title: Re: Understanding Chain Pitch
Post by: SawTroll on December 22, 2009, 01:04:30 PM
Quote from: Tim/South on December 20, 2009, 10:24:04 PM
........     If I buy a 50 ga bar for the Shindaiwa will I need to change sprockets as well?   .......

No, the sprockets vary with pitch (.325, 3/8" etc), and not with gauge (.050, .058 etc).
Title: Re: Understanding Chain Pitch
Post by: John Mc on December 22, 2009, 08:01:26 PM
Quote from: nmurph on December 20, 2009, 10:30:57 PM
gauge....the width of the drive link   .43, .50, .58, .63

You left out some zeros here. The gauge numbers should be .043, .050, .058, and .060
Title: Re: Understanding Chain Pitch
Post by: sawguy21 on December 24, 2009, 12:26:34 AM
Your 50 and 353 will run the same loop of chain , .325 pitch, and bar. The 372 will need 3/8. The Shindi will use .325 pitch but the drive link count will be different than the Husqvarnas. The bars are also different. As others have said, buying bulk chain and bucking your own loops really does not pay unless you are using a lot. You will also need the proper tools and some practice to get it right.
Title: Re: Understanding Chain Pitch
Post by: Tim/South on December 27, 2009, 01:38:05 PM
Thanks to all who have replied. I have gained some knowledge and that is always a good thing.

Quote from: sawguy21 on December 24, 2009, 12:26:34 AM
The Shindi will use .325 pitch but the drive link count will be different than the Husqvarnas. The bars are also different. As others have said, buying bulk chain and bucking your own loops really does not pay unless you are using a lot. You will also need the proper tools and some practice to get it right.
I removed the bar on the Shindi and it says 3/8 - 7 on the drive sprocket. The bar I bought on Baileys for the 272/372 is also listed to fit the Shindi 757.  Until this discussion I never thought to look on the drive sprocket and never realized different sprockets were used on the same make and model of saw.
I already have the breaker and spinner as well as other tools. I have made my own loops from spools at the local shop.
It was mostly the pitch part I was confused with. At the shop they simply told me which spool to make the chain from and I went from there. I never had to know the difference, just what to do.

Thanks Again for all the input.