Why would you want 3/8 instead of .325 on a 550?

[bsmith717]

I’m a novice at best I just do t get it. Are there more chain options in 3/8?

The narrow kerf (.050) also seems like a better choice than the wider .058. Wouldn’t a wider kerf would only make your saw have to work harder.

Please enlighten my day.

 

[Mad Professor]

I don't think the kerf is different, just the bar groove and chain drivers.

They do make 3/8 lo pro/picco chain with a narrower kerf. You need the corresponding bar and drive sprocket.

Lots of people like running 0.325 chain on 50cc saws. They recently made a narrow kerf version of that.

 

[bsmith717]

I don't think the kerf is different, just the bar groove and chain drivers.

They do make 3/8 lo pro/picco chain with a narrower kerf. You need the corresponding bar and drive sprocket.

Lots of people like running 0.325 chain on 50cc saws. They recently made a narrow kerf version of that.

Hey buddy, thanks for the response.

I was just mentioning the deal about the wider kerf because it really didn’t make sense to me to want to switch from the 050 to 058 just like 325 to 3/8.

I see people bad mouthing 325 all the time and it just seems silly to me. Actually there’s a guy on YouTube that switched to 3/8 and he showed his cutting speed went up by an appreciable amount.

 

[epo]

The thickness of the drive link at the bottom (aka gauge) does not determine the kerf width.
You need to specify what model of chain you are talking about.

As for Husqvarna, the chains and guide bars they offer that have a "narrow kerf" are described as Pixel.
Examples of Husqvarna's .325 Pixel chains: H30, SP33G ("X-Cut"). You should also use bars labeled Pixel with Pixel chains.

In the nomenclature used by Oregon, such chains and bars are described simply as Narrow Kerf (e.g. 95TXL chain).

In general, a narrower kerf for the same length of cut, means less material removed, and therefore less energy consumed.

 

[bsmith717]

The thickness of the drive link at the bottom (aka gauge) does not determine the kerf width.
You need to specify what model of chain you are talking about.

As for Husqvarna, the chains and guide bars they offer that have a "narrow kerf" are described as Pixel.
Examples of Husqvarna's .325 Pixel chains: H30, SP33G ("X-Cut"). You should also use bars labeled Pixel with Pixel chains.

In the nomenclature used by Oregon, such chains and bars are described simply as Narrow Kerf (e.g. 95TXL chain).

In general, a narrower kerf for the same length of cut, means less material removed, and therefore less energy consumed.

So a .050 chain does not remove less material compared to a .058 chain?

The bar/chain I have on mine is.

Husqvarna 596008966 RP16" BAR, HT250-66. 325, .050​

Husqvarna 531300437 16-inch H30-66 (95vp) Pixel Saw Chain, .325-Inch by .050

 

[epo]

So a .050 chain does not remove less material compared to a .058 chain?

The bar/chain I have on mine is.

Husqvarna 596008966 RP16" BAR, HT250-66. 325, .050​

Husqvarna 531300437 16-inch H30-66 (95vp) Pixel Saw Chain, .325-Inch by .050

It depends...
Your chain is of the Pixel type, which means it has a narrower kerf than Husqvarna (Oregon) .325/.050 "normal" chain, or H22.
Your guide bar, on the other hand, is IIRC not of the Pixel type, so, for example, one of the benefits of using this type of bar/chain combination, i.e. reduced weight, does not fully occur.
In addition, due to the reduced ratio of the kerf width to the width of the guide bar, you may have more problems with certain types of cutting (e.g. in bark).
If I were you, I would use a "regular" .325/.050 chain with this bar, i.e. Husqvarna H22 or Oregon 20 BPX/LPX/LGX.

 

[Mad Professor]

So a .050 chain does not remove less material compared to a .058 chain?

The bar/chain I have on mine is.

Husqvarna 596008966 RP16" BAR, HT250-66. 325, .050​

Husqvarna 531300437 16-inch H30-66 (95vp) Pixel Saw Chain, .325-Inch by .050

I believe the 0.325 NK chains have different cutters hence the kerf difference , like 3/8 vs 3/8 lo pro/picco I know the 3/8 have different chassis and require different drive sprockets and bar tips. Not sure on the NK 0.325?

 

[bsmith717]

It depends...
Your chain is of the Pixel type, which means it has a narrower kerf than Husqvarna (Oregon) .325/.050 "normal" chain, or H22.
Your guide bar, on the other hand, is IIRC not of the Pixel type, so, for example, one of the benefits of using this type of bar/chain combination, i.e. reduced weight, does not fully occur.
In addition, due to the reduced ratio of the kerf width to the width of the guide bar, you may have more problems with certain types of cutting (e.g. in bark).
If I were you, I would use a "regular" .325/.050 chain with this bar, i.e. Husqvarna H22 or Oregon 20 BPX/LPX/LGX.

Are you saying that husky gave me a bar that doesn’t match the chain???

 

[bsmith717]

I believe the 0.325 NK chains have different cutters hence the kerf difference , like 3/8 vs 3/8 lo pro/picco I know the 3/8 have different chassis and require different drive sprockets and bar tips. Not sure on the NK 0.325?

Also I thought that Lo pro/picco was just less height for the teeth/cutters.i up

 

[epo]

I believe the 0.325 NK chains have different cutters hence the kerf difference , like 3/8 vs 3/8 lo pro/picco I know the 3/8 have different chassis and require different drive sprockets and bar tips. Not sure on the NK 0.325?

That's not a good analogy, because a 3/8 LP ("Extended Pitch" saw chain) has as much to do with 3/8 as a .325 LP ("High Efficiency" saw chain) has to do with .325. Oregon not too long ago launched a .325 LP in the form of 80 TXL chain.

Yes, .325 NK chains has different cutters.

With .325 NK (95 TXL), you don't have to use another drive sprocket.

 

[epo]

Are you saying that husky gave me a bar that doesn’t match the chain???

Did you have the bar and chain in the original equipment of the saw, i.e. together in the box?
Yes, 3/8 LP/Picco/Mini/Hobby (e.g. 4mm file) has lower teeth than 3/8 (e.g. 5.5mm file) and they are incompatible with each other. .325 LP (4 mm file) has lower teeth than .325 (4.8 mm file) and they are incompatible with each other.
Oregon .325 NK (4.8 mm file) is compatible with .325 non-NK (4.8 mm file), but I wouldn't use the same guide bar for them.

 

[Mad Professor]

That's not a good analogy, because a 3/8 LP ("Extended Pitch" saw chain) has as much to do with 3/8 as a .325 LP ("High Efficiency" saw chain) has to do with .325. Oregon not too long ago launched a .325 LP in the form of 80 TXL chain.

Yes, .325 NK chains has different cutters.

With .325 NK (95 TXL), you don't have to use another drive sprocket.

3/8 7-pin rim and 3/8 7-pin picco/lo pro rim. Note different diameters, but same pitch. Chassis are different but same pitch. A 100' loops of each both have 1640 drivers, but the drivers will mismatch if you use the wrong sprocket. Same for bar tip sprockets.

 

[epo]

3/8 7-pin rim and 3/8 7-pin picco/lo pro rim. Note different diameters, but same pitch. Chassis are different but same pitch. A 100' loops of each both have 1640 drivers, but the drivers will mismatch if you use the wrong sprocket. Same for bar tip sprockets.

I don't know what your post is referring to.
After all, I wrote that 3/8 LP (Extended Pitch) is not and has never been compatible with full 3/8.
It was introduced by Oregon in the mid-1970s to reduce the cost of equipping small chainsaws with 1/4 chains.
A larger pitch (.375) than .250 meant fewer links per unit length of guide bar.
The design premise for the new type of chain was to keep the tooth size from 1/4 and use it with the already rather popular pitch, 3/8. There's a reason why the generally recommended 3/8 LP and 1/4 sharpening files are the same size: 5/32''.

Oregon's model 95 chain (NK), on the other hand, retains compatibility with the "normal" .325 system.

Recently Oregon introduced the Type 80 TXL chain (.325 Low Profile), which has the same pitch as the .325 (similar to 3/8 LP and 3/8), it is not compatible with the full .325.

 

[cscltd]

It should be noted that the 80txl chain (and Husqvarna's version SP21G) is .043 gauge and recommended on saws less than 3hp, which 550 is above that. The chain chassis is probably not strong enough for higher hp saws.

 

[epo]

It should be noted that the 80txl chain (and Husqvarna's version SP21G) is .043 gauge and recommended on saws less than 3hp, which 550 is above that. The chain chassis is probably not strong enough for higher hp saws.

That's right. These are .325 Low Profile chains, which are a new, different type of chain ("High Efficiency").

 

[echomeister]

what is special about the 80txl that it can't use a regular .043 bar and .325 sprocket.

 

[J D]

what is special about the 80txl that it can't use a regular .043 bar and .325 sprocket.

Same as 3/8 vs 3/8 low pro (picco)... the pitch is the same but the reduction of the chasis size changes the size of the rims /sprockets required. I suspect in the case of the new .325" variations the difference would be fairly minimal, although probably not insignificant.

 

[bsmith717]

We got an issue here. I literally just got this saw and tried cutting with it a couple days ago. 3.4 seconds into my first Rip the chain flew off and I haven’t messed with it till just now. This chain doesn’t seem to jive with this bar or this sprocket. It binds up almost as soon as I put it on, tighten the nuts and try to push it with my scrench.

 

[coffeebrk]

Bar and chain are fine, what sprocket do you have?

 

[epo]

We got an issue here. I literally just got this saw and tried cutting with it a couple days ago. 3.4 seconds into my first Rip the chain flew off and I haven’t messed with it till just now. This chain doesn’t seem to jive with this bar or this sprocket. It binds up almost as soon as I put it on, tighten the nuts and try to push it with my scrench.

In an earlier post you gave a different guide bar part number than the one in the photo....
This bar from the photo is the Pixel/Narrow Kerf type. This is evidenced by that tapering symbol to the right of the markings.
The chain is probably SP33G, so the chain and bar combination matches.

If you're having problems, make sure the drive sprocket is .325. Normally it should be, but if you don't know the history of the saw, it's better to check.