1 609 929 M40 | (23.10.07)
Bosch Power Tools
12
| English
Adjusting the Speed/Impact Frequency
(GSB 20-2 RE/GSB 20-2 RCE/GSB 20-2 RET)
The speed/impact rate of the switched on power
tool can be variably adjusted, depending on how
far the On/Off switch
7
is pressed.
Light pressure on the On/Off switch
7
results in
low speed/impact rate. Further pressure on the
switch increases the speed/impact rate.
Preselecting the Speed/Impact Frequency
(GSB 20-2 RE)
With the dial control for speed preselection
8
,
the required speed/impact frequency can be pre-
selected even during operation.
The required speed/impact frequency depends
on the material and the working conditions, and
can be determined through practical testing.
Electronic Speed Preselection
(GSB 20-2 RCE/GSB 20-2 RET)
With the speed dial for electronic speed prese-
lection
3
, the required speed/impact frequency
can be selected even if the machine is running.
The required speed/impact frequency depends
on the material and the working conditions, and
can be determined through practical testing.
Constant Electronic Control
(GSB 20-2 RCE/GSB 20-2 RET)
The constant electronic control keeps the prese-
lected speed and impact rate nearly constant be-
tween no-load and load conditions.
Electronic Torque Limitation/Speed Preselec-
tion (Torque Control) (GSB 20-2 RET)
Drilling with speed preselection:
Set
the selector switch
4
to the “Drilling”
symbol. The required speed can be
selected with the speed dial
3
; it can
also be adjusted during operation.
Screwdriving with torque limitation:
Set the selector switch
4
to the
“Screwdriving” symbol. The effective
torque at the drill spindle can be vari-
able adjusted with the dial control
3
during operation:
I
=low torque,
III
=high torque.
The maximum speed is automatically adapted to
the adjusted torque.
If the preselected torque is reached during
screwdriving, the machine switches off; the drill-
ing tool no longer rotates. If the load on the ma-
chine is then removed with the On/Off switch
7
still pressed, the drilling tool continues to run
only at very low speed for safety reasons.
After briefly releasing the On/Off switch
7
, the
next screw can be driven in with the same
torque.
For
screwdriving without torque lim-
itation
, turn the speed dial
3
to the
right stop. This setting is required,
when the torque in position
III
is not
sufficient.
Working Instructions
f
Apply the power tool to the screw/nut only
when it is switched off.
Rotating tool inserts
can slip off.
Tips
After longer periods of working at low speed, al-
low the machine to cool down by running it for ap-
prox. 3 minutes at maximum speed with no load.
For drilling in tiles, set the selector switch
2
to
the “Drilling” symbol. Do not switch over to the
symbol “Impact Drilling” or work with impact un-
til after drilling through the tile.
Use carbide tipped drill bits when working in
concrete, masonry and brick wall.
For drilling in metal, use only perfectly sharp-
ened HSS drill bits (HSS = High Speed Steel).
The appropriate quality is guaranteed by the
Bosch accessories program.
Twist drills from 2.5–10 mm can easily be sharp-
ened with the drill bit sharpener (see accesso-
ries).
OBJ_BUCH-129-002.book Page 12 Tuesday, October 23, 2007 2:57 PM
