Bosch GDR 18V-220 C Professional Notice Originale page 19

Selecting the working mode
The power tool has two preset working modes A and B (16).
You can also programme working modes for different applic-
Predefined working Meaning
mode (16)
A Auto Slow-down
B Auto Shut-off
Locking/unlocking the user interface
The user interface can be locked and unlocked using the
"Lock User Interface" function in the Bosch Toolbox app.
Locking and unlocking through the user interface:
Activate the "(Un-)Lock from tool" function in the Bosch
Toolbox app.
The function is now also enabled on the power tool.
To lock or unlock the user interface, press and hold both the
mode button (17) and the speed selection button (19) for
five seconds.
Note: If the "Lock User Interface" function is activated, the
reset to factory settings option on the power tool is automat-
ically deactivated.
Practical advice
Only apply the power tool to the screw/nut when the
u
tool is switched off. Rotating tool inserts can slip off.
The power tool with inserted Bluetooth
u
Module GCY 42 (accessory) is equipped with a radio
interface. Local operating restrictions, e.g. in aircraft
or hospitals, must be observed.
The torque depends on the impact duration. The maximum
achieved torque results from the sum of all individual
torques achieved through impact. Maximum torque is
achieved after an impact duration of 6–10 seconds. After
this duration, the tightening torque increases only minimally.
The impact duration is to be determined for each required
tightening torque. The tightening torque actually achieved
should always be checked with a torque wrench.
Guide values for maximum screw tightening torques
Figures given in Nm; calculated from the tensional cross-section; utilization of the yield point: 90% (with friction coefficient
µ = 0.12). As a control measure, always check the tightening torque with a torque wrench.
total
Property Classes Standard Screws/Bolts
according to
3.6 4.6
DIN 267
M6 2.71 3.61
M8 6.57 8.7
M10 13 17.5
Bosch Power Tools
ations and adjust existing modes via the Bosch Toolbox un-
der A and B (16).
To switch between the working modes A and B (16), press
the mode button (17).
Function
When using working mode A, the power tool reduces the
speed when tightening (impact mechanism in action). The
slow-down time can be adjusted via the controls in the Bosch
Toolbox app.
When using working mode B, the power tool automatically
stops as soon as the screw is screwed all the way in. The shut-
off time can be adjusted via the controls in the Bosch Toolbox
app.
Screw applications with hard, spring-loaded or soft seats
When the achieved torques in an impact series are measured
during a test and transferred into a diagram, the result is the
curve of a torque characteristic. The height of the curve cor-
responds with the maximum reachable torque, and the
steepness 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
together
– Lubrication conditions at the screw/bolt connection
The following application cases result accordingly:
– A hard seat is a metal-to-metal screw application which
uses washers. After a relatively short impact duration, the
maximum torque is reached (steep characteristic curve).
Unnecessary long impact duration only causes damage to
the machine.
®
Low Energy
– A spring-loaded seat is also a metal-to-metal screw ap-
plication but uses spring washers, disc springs, studs or
screws/nuts with conical seats. It is also called a spring-
loaded seat when extensions are used.
– A soft seat is a screw application of e.g. metal on wood or
a screw application that uses lead washers or fibre wash-
ers as backing.
For a spring-loaded seat as well as for a soft seat, the max-
imum tightening torque is lower than for a hard seat. Also, a
clearly longer impact duration is required.
5.6 4.8 6.6 5.8
4.52 4.8 5.42 6.02
11 11.6 13.1 14.6
22 23 26 29
High-strength Bolts
6.8 6.9 8.8 10.9
7.22 8.13 9.7 13.6
17.5 19.7 23 33
35 39 47 65
1 609 92A 8HZ | (14.12.2023)
English | 19
12.9
16.2
39
78