Bosch Professional GWS 21-230 H Original Instructions Manual page 12

12 | English
Switching on/off
To start the power tool, push the on/off switch (2) forward
and then press it down.
To lock the on/off switch (2) in position, push the on/off
switch (2) further forward.
To switch off the power tool, release the on/off switch (2);
or, if the switch is locked, briefly press the on/off switch (2)
and then release it.
Switch without locking mechanism (country-specific):
To start the power tool, push the on/off switch (2) forward
and then press it down.
To switch off the power tool, release the on/off switch (2).
Always check abrasive tools before using them. The
u
abrasive tool must be fitted properly and be able to
move freely. Carry out a test run for at least one
minute with no load. Do not use abrasive tools that are
damaged, run untrue or vibrate during use. Damaged
abrasive tools can burst apart and cause injuries.
Working Advice
Pull the plug out of the socket before carrying out any
u
work on the power tool.
Exercise caution when cutting slots in structural walls;
u
see the "Information on structures" section.
Clamp the workpiece if it is not secure under its own
u
weight.
Do not load the power tool so heavily that it comes to a
u
stop.
If the power tool has been subjected to a heavy load,
u
continue to run it at no-load for several minutes to
cool down the accessory.
Do not touch grinding and cutting discs until they have
u
cooled down. The discs can become very hot while work-
ing.
Do not use the power tool with a cut-off stand.
u
Rough grinding
Never use cutting discs for rough grinding.
u
The best rough grinding results are achieved with a set angle
of 30° to 40°. Move the power tool back and forth with mod-
erate pressure. This will ensure that the workpiece does not
become too hot or discolour and that grooves are not
formed.
Flap Disc
With the flap disc (accessory), curved surfaces and profiles
can be worked. Flap discs have a considerably higher ser-
vice life, lower noise levels and lower sanding temperatures
than conventional sanding sheets.
Cutting Metal
Always use the protective guard for cutting (13) when
u
cutting bonded abrasives.
When carrying out abrasive cutting, use a moderate feed
that is suited to the material being machined. Do not exert
pressure on the cutting disc and do not tilt or swing the
power tool.
1 609 92A 438 | (26.11.2018)
Do not attempt to reduce the speed of a cutting disc coming
to a stop by applying pressure from the side.
Provide sufficient dust extraction when cutting stone.
u
Wear a dust mask.
u
The power tool may be used only for dry cutting/grind-
u
ing.
For best results when cutting stone, use a diamond cutting
disc.
Operate the power tool only with dust extraction and also
wear a dust respirator.
The vacuum cleaner must be approved for the extraction of
stone dust. Suitable vacuum cleaners are available from
Bosch.
crete with a high pebble content, the diamond cutting disc
can overheat and become damaged as a result. This is
clearly indicated by circular sparking, rotating with the dia-
mond cutting disc.
If this happens, stop cutting and allow the diamond cutting
disc to cool down by running the power tool for a short time
at maximum speed with no load.
If work is noticeably slower and with circular sparking, this
indicates that the diamond cutting disc has become dull. You
can resharpen the disc by briefly cutting into abrasive mater-
ial (e.g. lime-sand brick).
Information on structural design
Slots in load-bearing walls are subject to DIN 1053 part 1 or
country-specific regulations. These regulations must be ob-
served under all circumstances. Seek advice from the re-
sponsible structural engineer, architect or construction su-
pervisor before starting work.
The power tool must always
work in an up-grinding mo-
tion. Otherwise, there is a
risk that it will be pushed
uncontrolled out of the cut.
For best results when cut-
ting profiles and rectangular
tubing, start at the smallest
cross section.
Cutting stone
Switch on the power tool
and position it with the
front part of the cutting
guide on the workpiece.
Move the power tool with a
moderate feed motion that
is suited to the material be-
ing machined.
When cutting especially
hard materials such as con-
Bosch Power Tools