Stihl MS 250 Notice D'emploi page 39

Maintaining and Sharpening
the Saw Chain
Sawing effortlessly with a properly
sharpened saw chain
A properly sharpened saw chain cuts
through wood effortlessly even with very
little pushing.
Never use a dull or damaged saw chain
– this leads to increased physical strain,
increased vibration load, unsatisfactory
cutting results and increased wear.
Clean the saw chain
N
Check the saw chain for cracks and
N
damaged rivets
Replace damaged or worn chain
N
components and adapt these parts
to the remaining parts in terms of
shape and level of wear – rework
accordingly
Carbide-tipped (Duro) saw chains are
especially wear-resistant. For an optimal
sharpening result, STIHL recommends
STIHL servicing dealers.
WARNING
Compliance with the angles and
dimensions listed below is absolutely
necessary. An improperly sharpened
saw chain – especially depth gauges
that are too low – can lead to increased
kickback tendency of the chain saw –
risk of injury!
MS 250
Chain pitch
The chain pitch marking (a) is embossed
in the area of the depth gauge of each
cutter.
Marking (a) Chain pitch
Inches
7 1/4 P
1 or 1/4 1/4
6, P or PM 3/8 P
2 or 325 0.325
3 or 3/8 3/8
4 or 404 0.404
The diameter of file to be used depends
on the chain pitch – see table
"Sharpening tools".
The angles of the cutter must be
maintained during resharpening.
Sharpening and side plate angles
A
a
B
A Sharpening angle
STIHL saw chains are sharpened with a
30° sharpening angle. Ripping chains,
which are sharpened with a 10°
sharpening angle, are exceptions.
mm
Ripping chains have an X in the
6.35
designation.
6.35
B Side plate angle
9.32
The correct side plate angle results
8.25
automatically when the specified file
9.32
holder and file diameter are used.
10.26
Tooth shapes
Micro = semi-chisel tooth,
e. g., 63 PM3, 26 RM3,
36 RM
Super = full chisel tooth,
e. g., 63 PS3, 26 RS,
36 RS3
Ripping chain, e. g.,
63 PMX, 36 RMX
The angles must be identical for all
cutters in the saw chain. Varying angles:
Rough, uneven running of the saw
chain, increased wear – even to the
point of saw chain breakage.
English
Angle (°)
A B
30 75
30 60
10 75
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