Stihl MS 251 Manual De Instrucciones página 53

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.
MS 251, MS 251 C
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.
File holder
Use a file holder
N
Always use a file holder (special
accessory, see table "Sharpening tools")
when sharpening saw chains by hand.
File holders have markings for the
sharpening angle.
Use only special saw chain files! Other
files are unsuitable in terms of shape
and type of cutting.
To check the angles
Angle (°)
A B
30 75
30 60
10 75
STIHL filing gauge (special accessory,
see table "Sharpening tools") – a
universal tool for checking sharpening
and side plate angles, depth gauge
setting, and tooth length, as well as
cleaning grooves and oil inlet holes.
English
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