3/8 chain 550 Mark 2

[wyk]

On 31/03/2019 at 10:43, 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.

 All chainsaw chain is 'slightly dull'. But more on that laters...

 

The less metal you have behind the chisel or the tip, the sooner it becomes dull when you are scraping wood with it. It wears, bends, dulls, hits nails etc. A very easy way to test it is get a loop of full chisel chain, and then get a loop of semi chisel. The semi chisel has more metal doing the cutting. Or do an NK/LoPro loop of 325 vs full kerf 325. Now go and get a long bar with 3/8 semi chisel on it and one with 404 semi chisel - the 404 will cut longer before it needs resharpening. It has less teeth over all, but the teeth have much more metal behind them.  Semi Chisel 404 lasts for freaking ever before you start to feel it need a sharpening compared to 3/8. Not the smoothest cutting, tho. But this stuff is always a compromise. Much of it is because it uses a large amount of the cutter to scrape vs a chisel bit, and also has a much larger surface that can take damage from the wood and it's impurities before it becomes inefficient. Another good example is chainsaw milling - you would have to be insane to use full chisel chain for it. You use full chipper to scrape out the wood against the grain, and because it lasts much, much longer doing it, even in 325 or LP.

 

The edge of metal wears the same when exposed to the same wood(assuming the same metal) - so the more metal you have on the cutter, the slower the edge wears. I have seen a lot of peoples chainsaws in my lifetime, and very few can put a razors edge on them. Most cutting is done with a 'slightly dull' cutter - and the more metal there is up there, the more cutting a dull(ish) cutter can do before it goes blunt.  After all - a chainsaw is not cutting wood - it is chipping/scraping the wood out. Think more like a wood carvers chisel vs a razor. It doesn't need to be razor sharp unless you are doing detail work. It just needs to drag wood out. But it also won't work when it's blunted. More metal means less blunting.

 

It might not mean a huge amount if you cut very clean wood, but you sure as hell notice it when you are making firewood.

 

 

Edited April 3, 2019 by wyk

[Stubby]

14 minutes ago, wyk said:

 All chainsaw chain is 'slightly dull'. But more on that laters...

 

The less metal you have behind the chisel or the tip, the sooner it becomes dull when you are scraping wood with it. It wears, bends, dulls, hits nails etc. A very easy way to test it is get a loop of full chisel chain, and then get a loop of semi chisel. The semi chisel has more metal doing the cutting. Or do an NK/LoPro loop of 325 vs full kerf 325. Now go and get a long bar with 3/8 semi chisel on it and one with 404 semi chisel - the 404 will cut longer before it needs resharpening. It has less teeth over all, but the teeth have much more metal behind them.  Semi Chisel 404 lasts for freaking ever before you start to feel it need a sharpening compared to 3/8. Not the smoothest cutting, tho. But this stuff is always a compromise. Much of it is because it uses a large amount of the cutter to scrape vs a chisel bit, and also has a much larger surface that can take damage from the wood and it's impurities before it becomes inefficient. Another good example is chainsaw milling - you would have to be insane to use full chisel chain for it. You use full chipper to scrape out the wood against the grain, and because it lasts much, much longer doing it, even in 325 or LP.

 

The edge of metal wears the same when exposed to the same wood(assuming the same metal) - so the more metal you have on the cutter, the slower the edge wears. I have seen a lot of peoples chainsaws in my lifetime, and very few can put a razors edge on them. Most cutting is done with a 'slightly dull' cutter - and the more metal there is up there, the more cutting a dull(ish) cutter can do before it goes blunt.  After all - a chainsaw is not cutting wood - it is chipping/scraping the wood out. Think more like a wood carvers chisel vs a razor. It doesn't need to be razor sharp unless you are doing detail work. It just needs to drag wood out. But it also won't work when it's blunted. More metal means less blunting.

 

It might not mean a huge amount if you cut very clean wood, but you sure as hell notice it when you are making firewood.

 

 

Surely the more metal you have cutting the more wood you are cutting so the whole thing cancels itself out .  Small surface area cuts X amount of wood . Large surface are cuts X + amount of wood .  I think a dull chain is a dull chain  , beit Semi , round ground or square ground .

Edited April 3, 2019 by Stubby

[billpierce]

Surely the more metal you have cutting the more wood you are cutting so the whole thing cancels itself out .  Small surface area cuts X amount of wood . Large surface are cuts X + amount of wood .  I think a dull chain is a dull chain  , beit Semi , round ground or square ground .

Aye but some chains you notice pretty quick when dull others not so. Semi chis 404 seems to keep cutting pretty well on dirty stumps for example

[wyk]

10 minutes ago, Stubby said:

Surely the more metal you have cutting the more wood you are cutting so the whole thing cancels itself out .  Small surface area cuts X amount of wood . Large surface are cuts X + amount of wood .  I think a dull chain is a dull chain  , beit Semi , round ground or square ground .

It's the amount of cuts you are making before the teeth lose their ability to cut. Like I said, I am speaking from experience. Get some chain and dirty wood, two loops of different chain, the same saw, and you will experience the same thing. I very rarely use full chisel for firewood - it is just a waste of time.

[Stubby]

28 minutes ago, wyk said:

It's the amount of cuts you are making before the teeth lose their ability to cut. Like I said, I am speaking from experience. Get some chain and dirty wood, two loops of different chain, the same saw, and you will experience the same thing. I very rarely use full chisel for firewood - it is just a waste of time.

Yea I know Wes . I was just being a twatt .  I have used all cutters in all types over the years .

[Khriss]

Surely we need an expert opinion on this ! Where are our YouTube heroes ? k

[Khriss]

Given a choosing, full chisel 3/8 on large softwood one tooth up on sprocket,  then semi-chisel on hardwoods one tooth down on sprocket . Course , who knows what's on job sheet fr the morrow. K

[wyk]

6 hours ago, Stubby said:

Yea I know Wes . I was just being a twatt .  I have used all cutters in all types over the years .

Sometimes I am posting and working at the same time, or maybe pain killing at the same time, or maybe just being grumpy at the same time. I can come across a bit dismissive, I imagine. I surely don't know everything. I just try to share what I do know as well as I can.

I wouldn't worry about the twat thing - I think if we don't do our share of twattage on the itnerwebs, the thing will self destruct. At least, that's how it acts. It's such a needy thing, the interwebs.