3/8 or 404 which will cut faster

[brncreeper]

Depends on the operator, in this case the winning hotsaw was running 404.

http://www.youtube.com/watch?v=3WVF2A1gEU4

 

[2dogs]

Having nothing but questions, people always say .404 is stronger.

Isn't the dimension that .375 and .404 differ a length measure? So more meat to resist stretch? Is that how chains are really going to fail because of HP?

Thanks.

Yep. Look at the component that would break, the tie strap. Is it thicker om 404 than .375? Is the preset rivet thicker?

Treesling'r runs 3/8 on his pumped 880 and that is enough for me.

 

[MCW]

I've hit an iron dropper at full speed with my 3120 and .404" chain - it sheared the cutters off but didn't break. It takes one tough saw, or one hell of a dodgey (worn out) chain, to break in plain old wood without hitting anything. I can't remember the actual breaking load of chainsaw chain but I know it surprised me.
I know in softer woods like pine .404" will cut faster on my 3120 with a 36-42" bar. On hardwoods my 42" bar with 3/8" will cut faster than .404".
There is a time and a place for both chains. 3/8" will not outcut .404" in many situations on many saws and vice versa.

 

[MCW]

Yep. Look at the component that would break, the tie strap. Is it thicker om 404 than .375? Is the preset rivet thicker?

In answer to your questions (Carlton presets/tie straps);

3/8" Rivet Diameter = 4.38mm (.172")
Tie Strap Thickness = 1.45mm (.057")

.404" Rivet Diameter = 5.18mm (.204")
Tie Strap Thickness = 1.55mm (.61")

.404" way tougher than 3/8" but probably not necessary in most situations. If you've got a big enough saw to pull either chain at the same speed .404" will win in cutting speed and toughness. I mainly use semi chisel so some people may disagree when it comes to full chisel.

 

[stinkbait]

This is my theory:

Both 3/8" and .404" chain usually run about 0.025" raker depth, so each cutter is going to remove the same depth of wood with each pass. The .404" cutter will only remove more wood in the width of the kerf, but not depth, thus creating more unwanted drag for no reason. That said, if you are runing 3/8" chain on a 36" bar vs. .404" chain on a 36" bar, you will have more 3/8" cutters vs .404" cutters, moving at the same speed. With both chains removing the same depth of wood with each cutter then the 3/8" chain has to be faster. With 3/8": more cutters per foot, same chain speed, same raker depth wood removal, less drag with narrower kerf, it has to be faster.

 

[thomas72]

On my saws that are around 100cc they run .404. It is easier for me to sharpen when out cutting firewood and the chains tend to stay sharper longer. I do have one exception though. I run 3/8" .063 chain on my 090 with a 5' bar. Does really well but when you have to sharpen the chain it is agony.

 

[gilraine]

my expirence has shown 3/8 to be faster

 

[pioneerguy600]

The consensus so far seems to favor the 3/8" chain for being faster. I guess it would have to come down with the cuts being stopwatch timed while the chain was run on the same saw in the same wood and with the same bar length and similar tips[ sprocket or hard nosed], also the same drive tooth number on the sprocket. Otherwise there would still be disagreements on differences between the saws and their setups.
Pioneerguy600

 

[lesorubcheek]

I like Stinkbait's way of thinking. Here's my take on it.

Speed of cut is a function of
1. How fast the chain (or each cutter) is moving.
2. How deep each cutter is cutting (not width, but depth)
3. How many cutters are in a given length of chain.


and now, for the secondary items that effect the direct ones:
How fast the chain (or each cutter) is moving is a funtion of
1. Engine RPM
2. Sprocket circumference (distance chain is driven per rotation.)

How deep each cutter is cutting (not width, but depth) is a function of
1. Depth setting of rakers.
2. Filing angles on the chain
3. Sharpness of the chain.
4. Maybe some other stuff ????

How many cutters are in a given length of chain is a function of
1. Pitch of the chain.
2. Type (full, skip, etc..)

And, for some further indirect effects:
Engine RPM is a function of
1. Powerband of engine.
( you can go crazy here with stuff like tuning, cleanliness of air filter, environmental conditions, etc.).
2. Load placed on engine.


Load placed on engine is a function of
Anything adding drag or friction.......
1. width x depth of cutter as it contacts wood (larger area = more load)
2. number of cutters in contact with wood
3. type of bar (sprocket vs. solid nose)
(some other stuff here too such as bar groove condition, proper bar/chain oiling).

So you start seeing interdependencies of stuff all over the place. More cutters in the wood at a given time directly contributes to more wood removal, but as an indirect effect, adds to the load which may reduce an engine's RPM if it doesn't have adequete power and thereby reduce the chain speed which would actually reduce the amount of wood removal.

Its fun thinking about this stuff ain't it .

Dan

 

[Crofter]

I think chip clearance and length of individual cutter strokes is also part of the equation. Once a cutter gets full it quits cutting despite raker settings. Really opening up the gullet area on the cutters will give you faster cut times in larger wood. That might give the nod to 404 compared to 375 in some wood conditions.

 

[lesorubcheek]

I think chip clearance and length of individual cutter strokes is also part of the equation. Once a cutter gets full it quits cutting despite raker settings. Really opening up the gullet area on the cutters will give you faster cut times in larger wood. That might give the nod to 404 compared to 375 in some wood conditions.

Very good point! So do you think changing "How many cutters are in a given length of chain" to something like "How many cutters are actually cutting some wood at a given time", which then is a function of how many cutters in a given length, along with chip clearance capability and length of cutter stroke? I think I want to try to diagram this, but its starting to get a bit deeper than my present level of knowledge.

Dan

 

[Dibbs]

To test properly you need to keep the rim drive diameter the same on both test runs.
The closest link number/length is 14 x .375 = 5.25" and 13 x .404 = 5.252".

So, to test properly you need one saw, one bar, a 3/8 chain, a .404 chain, a 14 pin 3/8 rim and a 13 pin .404 chain so the rim diameter is a constant.

When someone bothers to test this out I'll be interested!


Anyway, an 8 tooth 3/8 will have more torque but less chain speed than an 8 tooth .404.
Yes, they have an equal number of cutters passing any point at a given RPM, but, the .404 has a greater volume for removal of chips, but, it is carrying extra weight which must be pulled around the bar and has a wider kerf.
Both these factors point to wasted HP/Torque when running .404 chain.

My money (on an even playing field) would be on 3/8.

 

[Crofter]

I dont know Dan, but considering how skip VS full comp chain seems to favor fewer cutters when big wood is involved makes me think there is something in the distance to the chip dump and gullet volume that complicates simple calculation of which chain should be faster. Same goes for .325 and 3/8.

 

[Dibbs]

Skip has less friction points so smaller saws can run bigger bars but at a cost of total time taken.

 

[MCW]

My 3120 still cuts faster with .404" semi chisel than 3/8" semi chisel on a 36" bar - definately in softer woods anyway like pine. Both using 7 pin rims but a .404" rim has a slightly larger diameter. Some good theories put forward though.
I know a lot of guys that run 3/8" on saws that came with .404". Once you're on bars over 42" I think 3/8" definately gets the nod (even though I run .404" skip on my 60"). Most of these guys run 3/8" so they only need one roll of chain in their shed across all their saws, not one roll of 3/8" and one roll of .404".

 

[heimannm]

With a longer bar (28" +) on a work saw I prefer .404 but I am pretty sure it is not faster, just a lot more durable, fewer joints to wear/stretch and fewer/bigger cutters to sharpen.

I am sure with both chains optimized it should be close but I suspect the .375 would be faster just because it is narrower and removes less wood.

How big of wood are we talking for this run anyway as I am sure that would make a difference. At some point a .375 chain will simply be full of chips and stop cutting where the .404 might be able to take bigger bites.

I hope the 3/8 is faster in small stuff since I bought an 18" bar to run on my SP125 for vintage saw races.

Can anyone help me come up with a 10T .375 rim sprocket, or even bigger?

Mark

 

[wayne reutner]

I was thinking the bigger teeth on the 404 would take a bigger chip,and not clog up as much on a longer bar.

 

[Brmorgan]

What about .404 chain in .058 gauge? I don't know if it's very easy to find anymore, but I have an old Pioneer chain of that size. I haven't measured but it appears to have a narrower kerf than the .063 on my 090.

Personally I vote for 3/8 in most cases, but I do like having the 28" .404 bar for the 066 when a particularly dirty log comes my way. 3/8 cuts noticeably better when I'm milling. As stated it is pulls a bit more torque, and doesn't bog the engine down as much. This lets me keep the saw in the powerband more, which in the end results in a faster average chainspeed and cut. My saws are just muffler modded though, so one that has really been worked on might do much better with .404.

 

[MCW]

What about .404 chain in .058 gauge? I don't know if it's very easy to find anymore, but I have an old Pioneer chain of that size. I haven't measured but it appears to have a narrower kerf than the .063 on my 090.

.404" in .058" guage still available (from Carlton anyway) in all styles. Chipper, Semi Chisel, Full Chisel, and Ripping. I need to get some in stock

 

[porky616]

can someone tell me the best angle to sharpen my 404 cutters at so they will cut thru bullet leads and steel spikes, just cant seem to get it right