Maintenance And Service - Bosch GDR 10,8-LI Original Instructions Manual

OBJ_BUCH-1146-002.book Page 9 Tuesday, December 18, 2012 12:58 PM
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 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
together
– Lubrication conditions at the screw/bolt connection
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
3.6
M 6 2.71
M 8 6.57
M 10
M 12 22.6
Tips
Before screwing larger, longer screws into hard materials, it is
advisable to predrill a pilot hole with the core diameter of the
2
thread to approx. / of the screw length.
3

Maintenance and Service

Maintenance and Cleaning
 Before any work on the machine (e. g., maintenance,
tool change, etc.) as well as during transport and stor-
age, set the rotational direction switch to the centre
position. Unintentional actuation of the On/Off switch can
lead to injuries.
 For safe and proper working, always keep the machine
and ventilation slots clean.
When the battery is no longer operative, please refer to an au-
thorised after-sales service agent for Bosch power tools.
If the machine should fail despite the care taken in manufac-
turing and testing procedures, repair should be carried out by
an after-sales service centre for Bosch power tools.
In all correspondence and spare parts order, please always in-
clude the 10-digit article number given on the type plate of
the machine.
After-sales Service and Application Service
Our after-sales service responds to your questions concern-
ing maintenance and repair of your product as well as spare
Bosch Power Tools
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.
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
parts. Exploded views and information on spare parts can al-
so be found under:
www.bosch-pt.com
Bosch's application service team will gladly answer questions
concerning our products and their accessories.
People's Republic of China
China Mainland
Bosch Power Tools (China) Co., Ltd.
567, Bin Kang Road
Bin Jiang District 310052
Hangzhou, P.R.China
Service Hotline: 4008268484
Fax: (0571) 87774502
E-Mail: contact.ptcn@cn.bosch.com
www.bosch-pt.com.cn
HK and Macau Special Administrative Regions
Robert Bosch Hong Kong Co. Ltd.
21st Floor, 625 King's Road
North Point, Hong Kong
Customer Service Hotline: +852 2101 0235
Fax: +852 2590 9762
E-Mail: info@hk.bosch.com
www.bosch-pt.com.hk
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
English | 9
= 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
1 609 92A 01P | (18.12.12)