3/8 chain 550 Mark 2

[wyk]

It's mostly witchcraft.

 

Now you'll have to pardon me. I'm meant to be dragging the MIL off to lunch in a bit.

[openspaceman]

1 hour ago, Woodworks said:

Not doubting that 3/8 works just trying to understand why.

IME the .325 was fine on the 254 15"  and it was also supplied with the 262 18" when it came out but in hardwoods breaking down tops I was able to break .325 so upgraded to 3/8.

[Stubby]

Its less sharpening coz its less cutters for a given bar length . 

[arboriculturist]

2 hours ago, Woodworks said:

Sorry to continue the derail but I still don't get why more metal keeps its edge longer. The leading edge of the cutter is the same on 3/8 just wider. I get there is more metal supporting it but don't get how this helps an edge last for longer. Do they take more wood off per cut so actually make fewer passes per inch of woodcut? My first saw that pulls a 3/8 is a 460 which does last a fair time between sharpens but I just put down to the fact it has the grunt to drag a slightly dull.

 

Not doubting that 3/8 works just trying to understand why.

There are less cutters with 3/8 for any given bar length of course but IMO 3/8 doesn't keep edge any longer. 3/8 removes deeper chips which is why they cut faster and this in combination with 3/8 cutting wider chips is why they need more Hp to run at optimum cutting speed. I can sharpen 325 much quicker than 3/8 which is why we use 3/8 where possible.

[Stubby]

4 minutes ago, arboriculturist said:

There are less cutters with 3/8 for any given bar length of course but IMO 3/8 doesn't keep edge any longer. 3/8 removes deeper chips which is why they cut faster and this in combination with 3/8 cutting wider chips is why they need more Hp to run at optimum cutting speed. I can sharpen 325 much quicker than 3/8 which is why we use 3/8 where possible.

When I said  " its less sharpening because there are less cutters for a given bar length "  I was just stating the maths of it . I don't necessarily mean its better . Personally ( and it is a personal thing ) I use .325 on 50cc and 60cc saws . I only step up to 3/8 on 70-90 cc saws . over 90cc I go .404 . 

[arboriculturist]

2 minutes ago, Stubby said:

When I said  " its less sharpening because there are less cutters for a given bar length "  I was just stating the maths of it . I don't necessarily mean its better . Personally ( and it is a personal thing ) I use .325 on 50cc and 60cc saws . I only step up to 3/8 on 70-90 cc saws . over 90cc I go .404 . 

Missed that post - We have spud ported saws and the 1st saw the 3/8 goes on is 357xp and the 660 ( Not ported (YET) ) has 3/8 also as even with 3/8, the 3ft bar on need to take it steady. ?

[Stubby]

Mine are Spud ported .  Thought that was a given ! ?

[Woodworks]

3 hours ago, arboriculturist said:

There are less cutters with 3/8 for any given bar length of course but IMO 3/8 doesn't keep edge any longer. 3/8 removes deeper chips which is why they cut faster and this in combination with 3/8 cutting wider chips is why they need more Hp to run at optimum cutting speed.

2

Thanks. That makes sense

[adw]

4 hours ago, Stubby said:

When I said  " its less sharpening because there are less cutters for a given bar length "  I was just stating the maths of it . I don't necessarily mean its better . Personally ( and it is a personal thing ) I use .325 on 50cc and 60cc saws . I only step up to 3/8 on 70-90 cc saws . over 90cc I go .404 . 

I think you hit the nail right on the head Stubby its what the manufacturers have always said re .325 3/8 and 404 on machine sizes.

[Mark_Skyland]

On 30/03/2019 at 18:03, eddystihl said:

 

Yep i know have it on my 550 now , but does the same rim fit on the mark 2

 

Yes, the rim is the same so as long as you have the small spline rim there is no issue.

 

In regards to using a 3/8 chain we did that with our 560 on a 20" bar. It had more than enough power to run it and its easier to sharpen IMO. Main advantage is that a bigger chain can take more abuse, in the arb world that can make more of a difference than in the forestry side of things imo. Think of it this way, if your stihl ms150 chain hits a nail its more or less written off, do that with a 660/395 and a quick brush with a file and you're good to go. There were always plenty of nails, stones and soil in domestic trees than I cared to like for.