Chain Pitch, What's the Difference?

[blsnelling]

A 325 8 pin is real close to 3/8 7 pin in chain speed and I'd think the 3/8 7 pin would put less load on the saw as there will be less teeth in the wood. We were talking about 325 7 pin compared to 3/8 7 pin. Steve

No. The 3/8 cuts a wider curf and is a heavier chain. A .325 8-pin cuts faster than a 3/8 7-pin on my modified 260.

3/8 lopro is very lighweight chain designed for small saws. It has a very narrow curf. It would likely stretch too much for use on larger saws.

.325 is a much heavier chain but still smaller than regular 3/8. The teeth are close together, but it cuts a narrower curf. It is used on most mid-sized saws like 250/260. It definately puts less drag on a saw than 3/8.

3/8 is used on saws from 361 to 660. Some put it on a 260 but I found through timed cuts that it slows my saw down, even with a square grind. Some also use it on big saws like the 084/880 because it has a narrower curf than .404 chain.

.404 is even larger than 3/8 and is found on the largest saws. It's usually only found on saws like the 084/880 but sometimes on a 660. It cuts a very wide curf and requires a powerful saw to pull it.

Something else to consider is that the larger the chain, the more durable they are. A .404 will last longer and stay sharper longer than a 3/8 in nast conditions. A little 3/8 lopro picco dulls extremely easy. Some have even been know to loose teeth. It's all based on the size saw and the needs of your cutting.

 

[Stihl Alive]

I run 3/8 on all my saws, including the 16" on the MS290, though its a safety chain. I have found that if you use the saw for mostly limbing and trimming, .325 is better because the 3/8 tends to "snatch" smaller looser branches instead of cutting. Where the slimmer 325 might just slice them off.


//adam

 

[PB]

How will that effect how the chain rides on the sprocket?

Not sure if someone already answered or not, but the length between the drive links is different. Imagine a sprocket with large teeth and a roller chain with links that are very close together. The chain won't fit correctly into the sprocket and will result in poor performance or the chain will jump ship and possibly hurt you or someone else.

You need to run a .325 sprocket for .325 chain and you need a 3/8" sprocket for 3/8" chain.

The main sizes for chain are 3/8" low profile (this is used on really small saws, don't confuse it with regular 3/8" chain, .325 used on saws usually up to 60cc, 3/8" used on saws about 60cc or larger, and .404 chain used on really big saws. All the sizes listed, need to have a corresponding sprocket with the same size in order to correctly move the chain around the bar.

 

[blsnelling]

Not sure if someone already answered or not, but the length between the drive links is different. Imagine a sprocket with large teeth and a roller chain with links that are very close together. The chain won't fit correctly into the sprocket and will result in poor performance or the chain will jump ship and possibly hurt you or someone else.

You need to run a .325 sprocket for .325 chain and you need a 3/8" sprocket for 3/8" chain.

The main sizes for chain are 3/8" low profile (this is used on really small saws, don't confuse it with regular 3/8" chain, .325 used on saws usually up to 60cc, 3/8" used on saws about 60cc or larger, and .404 chain used on really big saws. All the sizes listed, need to have a corresponding sprocket with the same size in order to correctly move the chain around the bar.

+1

 

[mountainlake]

No. The 3/8 cuts a wider curf and is a heavier chain. A .325 8-pin cuts faster than a 3/8 7-pin on my modified 260.

3/8 lopro is very lighweight chain designed for small saws. It has a very narrow curf. It would likely stretch too much for use on larger saws.

.325 is a much heavier chain but still smaller than regular 3/8. The teeth are close together, but it cuts a narrower curf. It is used on most mid-sized saws like 250/260. It definately puts less drag on a saw than 3/8.

3/8 is used on saws from 361 to 660. Some put it on a 260 but I found through timed cuts that it slows my saw down, even with a square grind. Some also use it on big saws like the 084/880 because it has a narrower curf than .404 chain.

.404 is even larger than 3/8 and is found on the largest saws. It's usually only found on saws like the 084/880 but sometimes on a 660. It cuts a very wide curf and requires a powerful saw to pull it.

Something else to consider is that the larger the chain, the more durable they are. A .404 will last longer and stay sharper longer than a 3/8 in nast conditions. A little 3/8 lopro picco dulls extremely easy. Some have even been know to loose teeth. It's all based on the size saw and the needs of your cutting.

Don't know if that .015 wider kerf makes that much difference, maybe a combination of a slightly smaller kerf, a little lighter chain and 1 more tooth in the wood in a 12" cut that make 325 cut faster. Steve

 

[Termite]

mountainlake

I like your answer mountainlake. An observation, the cutters on .375 is much taller but only .015" wider. I am guessing this is for chip discharge? To me my 401 cuts much better with .325 chisel than any of the narrow kerf chains I have tried.
"Limb cutting" a tree is different if you are just after saw logs or cutting the tops for firewood and then dragging the butts to be sawed. What seems most efficient to me is to saw the tops into firewood length with my 401. It is three pounds lighter than my 5100. Then when the wood gets big, finish with the 7900,I don"t even have to bend over with a 24inch bar.I have not been using the 50cc saw at all. But if I was to take only one saw to the woods to do this task it would be my 262xp. Sorry if I am off topic.

 

[heimannm]

More chain stuff

Brad touched on the topic of durability. Smaller chain pitch will have more and smaller rivets, so those chains will be subject to more "stretch" all other things being equal. Larger pitch chain will have larger rivets and few total per loop, so those chains will "stretch" less. The bearing portion of the rivet in most 1/2" pitch chain is 1/4" diameter.

I like to use big chain (.404) in my higher HP/high torque saws to avoid problems with excessive wear of the rivets and holes in the drive links where the chain pivots. All of my gear drive saws are fit with 1/2" pitch chain, again these are really high torque applications and the tensile strength of the chain must be high.

The last chain I broke was a .375 running on my Jonsered 930. The chain was pretty well worn out at that point but it literally pulled the hole right out of the drive link.

For smaller, high speed saws the smaller pitch chain will work wonders, but big saws with lots of grunt will need a chain up to the task. Larger pitch chain also translates to fewer cutters which makes filing a bit easier.

Can someone remind me the real difference between 3/8LP and standard 3/8 chains? I know I've read the LP is slightly smaller pitch, but I think Troll debunked that one, seems both are in fact .365"? Is it all in the design of the drive link? Can someone explain?

Mark

 

[046]

here's a useful guide. measure 3 links, then divide by 2 to get pitch. then measure width of bar groove and/or chain guide rail on bottom of chain to find gauge size. note they could be worn.

when in doubt about tolerances... start with a new chain and new bar to see what correct fit should be. if rail slot is too large, there's a tool available to tighten up. then draw file and/or grind bar back flat.

http://reviews.ebay.co.uk/Selecting-Chainsaw-Chain_W0QQugidZ10000000007417824

 

[heimannm]

???

From the afore mentioned article:

"It is vital that you fit LP chain if your bar requires this. The nose radius on a LP bar is smaller than a standard bar, normal chain will not fit round the sprocket properly as cutters are too high/deep. You can often fit LP chain to a standard bar with no ill effects (but standard chain cuts faster) but many saws have a smaller (6 tooth) drive sprocket on engine when running 3/8" Low Profile chain, a Standard profile chain will not mesh on this sprocket, and a Low Profile chain may not mesh properly on a standard profile saw sprocket (not a good move to fit LP chain on a standard bar anyway). "

I still don't know why...I would like to know, that's just the kind of person I am.

Mark

 

[SawTroll]

...

Can someone remind me the real difference between 3/8LP and standard 3/8 chains? I know I've read the LP is slightly smaller pitch, but I think Troll debunked that one, seems both are in fact .365"? Is it all in the design of the drive link? Can someone explain?

Mark

Both are .367 really, .375 is just an interpretation of 3/8, and .365 is used by some to differentiate the LP from the regular.

The drivers (and every other part) are different, and they use different size sprockets because the regular one rides higher on the sprocket than the LP.

 

[JONSEREDFAN6069]

can some one take a pic and post it with the different chain's skip chisel square grind thanx

 

[mountainlake]

Both are .367 really, .375 is just an interpretation of 3/8, and .365 is used by some to differentiate the LP from the regular.

The drivers (and every other part) are different, and they use different size sprockets because the regular one rides higher on the sprocket than the LP.

My calculator says 3/8 and 375 are the same, I think 3/8 is a interpretation of .367 and started getting call .375 after 3/8 came along. Steve

 

[SawTroll]

My calculator says 3/8 and 375 are the same, I think 3/8 is a interpretation of .367 and started getting call .375 after 3/8 came along. Steve

Yup, going one step further back than I did...:agree2:

 

[pgg]

3/8 and 3/8LP, both have the same pitch, rivets spaced the same distance, the LP stuff just smaller and lighter

 

[atvdave]

Newbie here with a ?

Sorry to hijack but I have a question.

I have a Dolmar 5100s on order and I want a chain that will cut fast. I'm not sure of the pitch (rookie mistake) but it's a 20" bar.

What chain would work best for me? I'll be using my small craftsman for the small stuff, and using the 5100s for larger stuff like trunks.

Also, is there a place on the web that will educate me on different types of chain? like chisel, semi chisel, ect....?

Thanks
Dave

 

[stihlboy]

Sorry to hijack but I have a question.

I have a Dolmar 5100s on order and I want a chain that will cut fast. I'm not sure of the pitch (rookie mistake) but it's a 20" bar.

What chain would work best for me? I'll be using my small craftsman for the small stuff, and using the 5100s for larger stuff like trunks.

Also, is there a place on the web that will educate me on different types of chain? like chisel, semi chisel, ect....?

Thanks
Dave

oregon has some info

 

[treehugger865]

I ran an MS280 for a while with the .325 pitch and a low kick back chain. I switched to a full chisel thinking this would speed up the saw but it just didn't seem to have the same power afterwards. In comparison I bought an MS361 with a full chisel chain and still it didn't feel much different than the 280 with the low kick chain. I guess the extra drags on the low k/b chain makes it easier to keep the rpm's up where they need to be for these newer saws.