16 ENGLISH
Sharpening the saw chain
Sharpen the saw chain when:
• Mealy sawdust is produced when damp wood is
cut;
• The chain penetrates the wood with diculty, even
when heavy pressure is applied;
• The cutting edge is obviously damaged;
• The saw pulls to the left or right in the wood.
(caused by uneven sharpening of the saw chain or
damage to one side only)
Sharpen the saw chain frequently but a little each time.
Two or three strokes with a le are usually sucient for
routine resharpening. When the saw chain has been
resharpened several times, have it sharpened in our
authorized service center.
Sharpening criteria:
WARNING: An excessive distance between
the cutting edge and depth gauge increases the
risk of kickback.
22
1
1
3
1
► 1. Cutter length 2. Distance between cutting edge
and depth gauge 3. Minimum cutter length (3 mm
(1/8"))
— All cutter length must be equal. Dierent cutter
lengths prevent the saw chain from running
smoothly and may cause the saw chain to break.
— Do not sharpen the chain when the cutter length
has reached 3 mm (1/8") or shorter. The chain
must be replaced with new one.
— The chip thickness is determined by the distance
between the depth gauge (round nose) and the
cutting edge.
— The best cutting results are obtained with following
distance between cutting edge and depth gauge.
• Chain blade 90PX : 0.65 mm (0.025″)
• Chain blade 91PX : 0.65 mm (0.025″)
• Chain blade 25AP : 0.65 mm (0.025″)
30
30
55
55
— The sharpening angle of 30° must be the same on
all cutters. Dierent cutter angles cause the chain
to run roughly and unevenly, accelerate wear, and
lead to chain breaks.
— Use a suitable round le so that the proper sharp-
ening angle is kept against the teeth.
• Chain blade 90PX : 55°
• Chain blade 91PX : 55°
• Chain blade 25AP : 55°
File and le guiding
— Use a special round le (optional accessory) for
saw chains to sharpen the chain. Normal round
les are not suitable.
— Diameter of the round le for each saw chain is as
follows:
• Chain blade 90PX : 4.5 mm (3/16″)
• Chain blade 91PX : 4.0 mm (5/32″)
• Chain blade 25AP : 4.0 mm (5/32″)
— The le should only engage the cutter on the for-
ward stroke. Lift the le o the cutter on the return
stroke.
— Sharpen the shortest cutter rst. Then the length
of this shortest cutter becomes the standard for all
other cutters on the saw chain.
— Guide the le as shown in the gure.
1
2
► 1. File 2. Saw chain
— The le can be guided more easily if a le holder
(optional accessory) is employed. The le holder
has markings for the correct sharpening angle of
30° (align the markings parallel to the saw chain)
and limits the depth of penetration (to 4/5 of the
le diameter).