Working Advice - Bosch GDS 18 E Professional Originalbetriebsanleitung

OBJ_BUCH-544-003.book Page 11 Tuesday, August 28, 2012 4:39 PM
Switching On and Off
– To start the machine, press the On/Off switch 5 and keep
it pressed.
– To switch off the machine, release the On/Off switch 5.
When not using the power tool, switch it off in order to save
energy.
Adjusting the Speed
The speed of the switched on power tool can be variably ad-
justed, depending on how far the On/Off switch 5 is pressed.
Light pressure on the On/Off switch 5 results in a low rotation-
al speed. Further pressure on the switch results in an increase
in speed.
Preselecting the Speed
The required speed can be preselected with the thumbwheel
6 (also while running).

Working Advice

Before any work on the machine itself, pull the mains
plug.
Apply the power tool to the screw/nut only when it is
switched off. Rotating tool inserts can slip off.
The torque depends on the impact duration. The maximum
achieved torque results from the sum of all individual torques
achieved through impact. The maximum torque is achieved
after an impact duration of 3–5 seconds. After this duration,
the tightening torque is increased only minimally.
However, the transmission housing heats up noticeably.
Note: The consequences of excessive heating-up are high
wear of all hammer mechanism components and a high re-
quirement of lubricant.
The impact duration is to be determined for each required
tightening torque. The actually achieved tightening torque is
always to be checked with a torque wrench.
Reference Values for Maximum Screw/Bolt Tightening Torques
Calculated from the tensional cross-section; utilization of the yield point 90 % (with friction coefficient μ
measure, always check the tightening torque with a torque wrench.
Property Classes accord- Standard Screws/Bolts
ing to DIN 267
M6 2.71
M8 6.57
M10
M12 22.6
M14
M16
M18
M20 107
Tips
Torque rods have shanks with precisely calibrated, reduced
diameters. Thus, they act torque-limiting. A torque rod is
placed between the impact wrench and the bit.
Bosch Power Tools
Screw Applications with Hard, Spring-loaded or Soft Seat
When in a test, the achieved torques in an impact series are
measured and transferred into a diagram, resulting in the
curve of a torque characteristic. The height of the curve corre-
sponds with the maximum reachable torque, and the steep-
ness indicates the duration in which this is achieved.
A torque gradient depends on the following factors:
– Strength properties of the screws/nuts
– Type of backing (washer, disc spring, seal)
– Strength properties of the material being screwed/bolted
– Lubrication conditions at the screw/bolt connection
The following application cases result accordingly:
– A hard seat is given for metal-to-metal screw applications
– A spring-loaded seat is given for metal-to-metal screw ap-
– A soft seat is given for screw applications, e. g., metal on
For a spring-loaded seat as well as for a soft seat, the maxi-
mum tightening torque is lower than for a hard seat. Also, a
clearly longer impact duration is required.
3.6 4.6 5.6 4.8
3.61 4.52 4.8
8.7 11 11.6
13 17.5 22 23
30 37.6 40
36 48 60 65
55 73 92 98
75 101 126 135
143 178 190
Rule of thumb for the application: Core diameter of the
screw/bolt = effective diameter of the torque rod. The impact
duration is to be determined through practical testing.
The thumbwheel 6 must be set to max.
together
with the use of washers. After a relatively short impact du-
ration, the maximum torque is reached (steep characteris-
tic curve). Unnecessary long impact duration only causes
damage to the machine.
plications, however with the use of spring washers, disc
springs, studs or screws/nuts with conical seat as well as
when using extensions.
wood or when using lead washers or fibre washers as back-
ing.
6.6 5.8 6.8 6.9
5.42 6.02 7.22 8.13
13.1 14.6 17.5 19.7
26 29 35 39
45 50 60 67
72 79 95 107
110 122 147 165
151 168 202 227
214 238 286 320
English | 11
= 0.12). As a control
total
High-strength Bolts
8.8 10.9 12.9
9.7 13.6 16.2
23 33 39
47 65 78
80 113 135
130 180 215
196 275 330
270 380 450
385 540 635
1 609 92A 02X | (28.8.12)