Square ground chisel chain vs. round ground chisel chain

[Philbert]

I've noticed round chain seems to wander around more on big cuts. Try matching three or four bucking cuts with a 36" bar on a big butt cut and you will see what I mean. This has been my experience, yours may vary.

Never had a problem with the chain wandering if it was sharpened uniformly, and if the bar was in good shape (square rails, groove not worn out, etc.). I've seen a lot of hand filed chains where the cutters on one side were different lengths or angles than those on the other side.

Philbert

 

[madhatte]

I would hazard the guess that square seems to cut straighter specifically because it's almost always ground rather than filed. Consistency means consistency, if you catch my meaning. A good round ground chain cuts well.

 

[bnmc98]

So here were the results:
-Oregon full-skip chisel chain round ground. 1st cut=18.45 seconds, 2nd cut =17.19 seconds / average time was 17.82 seconds. (I only did two cuts with this chain vs. the others I did five cuts)
-Stihl full-skip chisel chain round ground. 1st cut =17.92 seconds, 2nd cut=17.65, 3rd cut =17.40 seconds, 4th cut =18.70, 5th cut =18.50 seconds / average time was 18.03 seconds.
-Stihl full-skip chisel chain square ground brand new. 1st cut =18.74 seconds, 2nd cut =17.32 seconds, 3rd cut =16.05 seconds, 4th cut =15.09 seconds, 5th cut =16.32 seconds / average time was 16.70 seconds.

Not to be a jerk, but I never understood how timing cuts can be accurate, especially down to .01 seconds.
To me unless you have a machine that applies the same pressure for every cut with the same drop speed of the saw, then there's the whole chain sharpening thing. I don't see how it really can be a comparison.
Human error factor.

 

[Clint C.]

Not to be a jerk, but I never understood how timing cuts can be accurate, especially down to .01 seconds.
To me unless you have a machine that applies the same pressure for every cut with the same drop speed of the saw, then there's the whole chain sharpening thing. I don't see how it really can be a comparison.
Human error factor.

I agree with you 100% but my test was one of the best I have seen done. I would love to see a test done by real engineers at Oregon or Stihl using machines providing exact pressure and an exact timing methods. I guess in my particular case I only did it to see for myself what the real deal was with square ground chain and I wanted to post it so other folks could use it for whatever.

It seems like a lot of people talk about how good square chisel is and I have seen very, very few tests showing if it is really fast.

 

[Philbert]

You have to have calibrated, instrumented machines in a controlled test environment, to get highly accurate, precise results. This includes identical test wood! But if you make lots of cuts, multiple trials, side-by-side, with the same saw, same operator, etc., you can get some reasonable feedback. I have noted significant performance differences doing this, although, I did not try to quantify them to multiple decimal places. At GTG races, it is often more about the technique than the saw or the chain!

Philbert

 

[Gypo Logger]

Round filed isfaster than square, because it takes alot less time to file.
Also, just by virtue of having a square chain doesn't mean its faster. Its more about the guy doing the filing.
Just because I have a 3120 doesn't mean someone cant beat me with their 372.

 

[Philbert]

It's hip to be square . . . .

Philbert

 

[catbuster]

I use semi-(round) chisel chain. I don't keep a chain grinder with me, or even on the truck. I carry a file and a raker gauge, take a couple strokes per cutter and knock the rakers down every once in a while. A square chain *does*, unquestionably cut better. But when I cut blowdown and bulldozed logs in dirty areas I can't lose my working corner with every cut-which is what I was doing when I tried square. And... Don't even think about bringing square on the fire line. If not being able to take a hazard tree down due to a dull chain is your cup of tea... I guess be my guest, but you won't work long.

In regards to boring cuts... I say man up, trade your Victoria's Secret thongs for some Hanes boxer briefs and go to work instead of bellyaching about it.

Sincerely,

Everyone's favorite multi-faceted business owner,

The Cat

 

[Jim Timber]

Square has better edge support, since all else is equal on the tooth profile itself with round full chisel. The hollow profile of round ground leaves a very sharp edge with a thinner cross section that's easier to roll over (dull). Once the edge is rolled, the cutter is ripping instead of slicing at the fibers and the performance suffers.

Square ground leaves a thicker edge at it's point, which has more support behind it so it doesn't roll over as easily. This is why they stay sharper longer and seem to perform better; because to the user, they do.

Semi-chisel is a work around to the problem of the tip going dull on round ground full chisel: remove that weak point with a radius. The resulting cutter isn't as aggressive in pulling into the fibers, but that tip also doesn't roll over at the first sign of dirt either. So it too stays sharper longer.

Think of it like a bush knife vs a scalpel. The bush knife can be made plenty sharp, and it's thick blade will keep an edge with a decent amount of chopping. The scalpel can be made very sharp, but as soon as you mash it into something hard it's going to be duller than the bush knife.