Reactive Forces; Pulling Away; Reduce The Risk Of Kickback - Stihl TS 420 Original Instruction Manual

Never leave the machine unattended
with the engine running. Switch off the
engine before leaving the machine
(e. g., for a break).
Before putting the cut-off machine down
on the ground:
– Switch off engine
– Wait until the cutting wheel has
come to a standstill or brake the
cutting wheel until it comes to a
standstill by carefully touching a
hard surface (e. g., concrete slab)
Inspect cutting wheel fre-
quently – replace
immediately if there is
evidence of cracking,
warping or other damage
(e. g., overheating) – risk
of accident due to
breakage!
In the event of changes in cutting
behavior (e. g., increased vibration,
reduced cutting performance), stop work
and eliminate the causes of the
changes.

Reactive forces

The most frequently occurring reactive
forces are kickback and pull-in.
Dangers of kickback
Kickback can result in fatal cuts.
Working safely with cut-off machines
Kickback occurs when the cut-off
machine is suddenly thrown up and back
in an uncontrolled arc towards the
operator.
Kickback occurs if, for example, the
cutting wheel
– becomes jammed – above all in the
upper quarter
– is severely braked through frictional
contact with a solid object

Reduce the risk of kickback

– Work cautiously and methodically
– Hold the cut-off machine firmly with
both hands and maintain a secure
grip
– Do not use the upper quarter of the
cutting wheel for cutting. The cutting
wheel must be introduced into the
cut with extreme care, without
twisting and without pushing
– Always be aware that the object to
be cut may move and other factors
may cause the cut to close and jam
the cutting wheel.
– The object to be cut must be
secured and supported so that the
cut remains open during and after
cutting
– Work with water and wet cutting
when using diamond cutting wheels
– Depending on version, composite
resin cutting wheels are suitable for
dry cutting or wet cutting only.
Always use wet cutting with
composite resin cutting wheels that
are suitable only for wet cutting

Pulling away

The machine pulls forward, away from
the user, when the cutting wheel
touches the object to be cut from above.
English
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