The Granberg is the pick for best overall. It sharpened a full chain in just
over 4 minutes, faster than anything else here, and the chain it produced cut
the test log in 10.8 seconds — a little over a second off a brand new chain at
9.75, and within a third of a second of the best result in the test. Because
the grinder clamps to the bar and works off a dialed angle and a height stop,
it takes the same amount of metal off every tooth at the same angle, which a
free-hand file or a hand-held rotary tool cannot do. Its 12-volt motor measured
close to 18,500 RPM against a claimed 24,000, and its threaded sharpening
stones have affordable replacements from several brands.
For value, the Stihl at $49 is remarkable: a hand file that put the chisel back
to a like-new edge in 8 minutes, scored 295 on the sharpness tester, and turned
in a 10.6-second cut, second only to the Timberline among sharpened chains. It
is also the only tool in this group that files the depth gauges while it
sharpens, which matters more with every sharpening — as the top of the cutter
slopes back and gets lower, an unmaintained raker leaves the tooth taking a
thinner and thinner bite until it stops cutting. The Timberline earns its $125
on edge quality and build, with the sharpest chain in the test at 225 and the
fastest sharpened cut at 10.5 seconds, but just over 15 minutes per chain is a
lot of cranking. The $40 EzzDoo is the compromise pick if speed of sharpening
is the priority — 6 minutes per chain and a 15.48-second cut — and the $30
PRETEC does much the same job cordless at 14.7 seconds, with the caveat that
its sharpening stones arrive bent and wear out fast.
Two cautions. A plain steel file is asking a lot of a modern chain: 17 minutes
with the Honoson set left the chisel at 460 and a 27.1-second cut that got
slower on each successive pass, because the file itself dulled against the hard
chain metal. The Totile is a $30 copy of the Timberline, down to the logo
reproduced in its instruction sheet, and it is a false economy — its carbide
cutter is too small in diameter to reach the top of the chisel, so 26.5 minutes
of cranking produced a chain that still took 36.1 seconds, against 50 seconds
for the untouched dull chain. Finally, note that no sharpened chain quite
matched a new one, so a sharpener is best judged on how close it gets and how
long it takes to get there.