Stihl HT 250 Manual De Instrucciones página 33

Chain pitch
The chain pitch (a) is marked on the
depth gauge end of each cutter.
Mark (a) Chain pitch
inch
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
Select file diameter according to chain
pitch – see table "Sharpening Tools".
You must observe certain angles when
resharpening the chain cutter.
Filing and side plate angles
A
B
A Filing angle
HT 250
STIHL saw chains are sharpened to a
filing angle of 30°. Exceptions are
ripping chains with a filing angle of 10°.
Ripping chains have an X in their
designations.
B Side plate angle
a
The correct side plate angle is obtained
automatically if you use the prescribed
file holder and file diameter.
Cutter shapes
Micro = semi chisel cutter,
e.g. 63 PM3, 26 RM3,
71 PM3
mm
Super = chisel cutter, e.g.
6,35
63 PS3, 26 RS, 36 RS3
6,35
Ripping chain, e.g.
63 PMX, 36 RMX
9,32
8,25
The angles must be the same on all
cutters. If the angles are uneven: Chain
9,32
will run roughly, not in a straight line,
wear quickly and finally break.
File holder
Use a file holder
N
A file holder must be used for manual
resharpening (see table "Sharpening
Tools"). The correct filing angles are
marked on the file holder.
Use only special saw chain sharpening
files. Other files have the wrong shape
and cut.
For checking angles
Angle (°)
A B
30 75
Use a STlHL filing gauge (special
30 60
accessory, see table "Sharpening
Tools"). This is a universal tool for
10 75
checking the filing and side plate angles,
depth gauge setting, cutter length and
groove depth. It also cleans the guide
bar groove and oil inlet holes.
File correctly
Select sharpening tools according
N
to chain pitch.
If you use an FG 2, HOS or USG
N
sharpener: Remove the chain from
the bar and sharpen according to
the instructions supplied with the
tool.
Clamp the bar in a vise if necessary.
N
Sharpen the chain frequently, take
N
away as little metal as possible –
two or three strokes of the file are
usually enough.
English
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