Maintenance And Servicing - Bosch GDR 14,4 V-EC Professional Manual Original

18 | English
Switching the "PowerLight" lamp on/off
Press the button (8) to activate the lamp (11). To switch
off the lamp (11), press the button (8) again.
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 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 is increased only minim-
ally.
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.
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.
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
M12 22.6 30
M14 36 48
M16 55 73
Tips
Before screwing larger, longer screws into hard materials, it
is advisable to pre-drill a pilot hole with the core diameter of
the thread to approx. 2/3 of the screw length.
Note: Ensure that no metal particles enter the power tool.
Belt clip
You can use the belt clip (3) to hang the power tool on a belt,
for example. You then have both hands free and the power
tool is always at hand.
Recommendations for optimal handling of the battery
Protect the battery against moisture and water.
Only store the battery within a temperature range of -20 to
50 °C. Do not leave the battery in your car in the summer, for
example.
A significantly reduced operating time after charging indic-
ates that the battery has deteriorated and must be replaced.
Follow the instructions on correct disposal.
1 609 92A 4PU | (16.10.2018)
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.
– 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
37.6 40 45 50
60 65 72 79
92 98 110 122

Maintenance and Servicing

Maintenance and Cleaning
Remove the battery from the power tool before carry-
u
ing out work on the power tool (e.g. maintenance,
changing tool, etc.). The battery should also be re-
moved for transport and storage. There is risk of injury
from unintentionally pressing the on/off switch.
To ensure safe and efficient operation, always keep
u
the power tool and the ventilation slots clean.
After-sales service and advice on using products
Our after-sales service responds to your questions concern-
ing maintenance and repair of your product as well as spare
parts. You can find explosion drawings and information on
spare parts at: www.bosch-pt.com
The Bosch product use advice team will be happy to help you
with any questions about our products and their accessor-
ies.
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
60 67 80 113
95 107 130 180
147 165 196 275
Bosch Power Tools
12.9
16.2
39
78
135
215
330