Sorry,
the beverage was flowing, I was PUI! Posting under the
influence.
But seriously, each chain model number, even from different
time periods, require a different file as the cutter height varies
with each chain, so I ask to see the chain. File diameter is
critical to get the angle correct, so I order boxes of files in
increments of 64's, and as the cutter is filed back, the diameter
of file should change.
As you look at the actual angle of the chisel, not from the top,
but from the side, should be @ %60, and any slight variation
of file diameter will alter this angle drastically.
With a grinder, this angle is made by the side of the stone/
wheel, so the only difference is in the depth of the "gullet".
I refuse to go into the theoretical physics of "chip travel", as
that is for other nimrods to explore, and I refuse to go there.
If one needs to know about the reality about what the chain
does and what happens to the chip of wood, just ask Art,
and listen.
But the best angles I have found, have been %60, on all of the
angles.
I have some old Windsor charts, which I based my work on,
which I can send anyone, if they ask.
I know ripping chain requires different angles, but I have none
of that around here.