Bosch GDR18V-1800 Instrucciones De Funcionamiento Y Seguridad página 12

2610052996_GDR GDS GDX 10/9/19 7:56 AM Page 12
trigger. During the oper a tion, hold the tool
firmly and exert light, steady pressure. Too
much pressure at low speed will stall the
tool. Too little pressure will keep the bit
from cutting and cause excess friction by
sliding over the surface. This can be
damaging to both tool and bit.
▼ DRIVING WITH VARIABLE SPEED
The technique is to start slowly, increasing
the speed as the screw runs down. Set the
screw snug ly by slowing to a stop. Prior to
driving screws, pilot and clearance holes
should be drilled.
Always hold the tool straight on the bolt to
be tightened.
The best method to determine the right
impacting/tightening duration is by means
of a trial. For small screws, the right
impacting/tightening duration can be
reached in less then 0.5 Sec. Therefore,
work with low RPM and switch the tool off
immediately when the screw is tight and
the impacting sound can be heard.
For screwing larger, longer wood screws into
hard material, pre-drilling is the best method.
▼ TIGHTENING TORqUE
The tightening torque depends on the
duration of the impacting/tightening action.
The largest tightening torque is achieved
after approx.
impacting/tightening action.
The torque build-up depends on the
following factors:
• Hardness of the bolts/nuts.
• Type of washer (disk washer, spring
washer, seal).
• Hardness of the material to be joined.
• Lubricating effect at the surfaces of
the junction.
This leads to the following application
cases:
Hard joining application: The joining of
metal to metal with a disk washer. The
maximum torque is reached after a relative
short impacting/tightening action.
Medium joining application: The joining of
metal to metal when using spring ring
washer, disk spring washer, stud bolts or
bolts/nuts with conical seats.
Soft joining application: The joining of e.g.
metal to wood or insulation material.
For middle or soft joining cases, the
Operating Instructions
6 to 10 Sec.
12
Fig. 8
FASTENING
WITH SCREWS
1. Drill 2/3 diameter and
2/3 of screw length for
soft materials, full
length for hard
materials.
Apply a slight
even pressure
when driving
screws.
maximum tightening torque is less than for
hard cases. Therefore, a longer impacting/
tightening action is necessary to arrive at
the maximum tightening torque.
▼ FASTENING WITH SCREWS
This procedure shown in (Fig. 8) will
enable you to fasten ma terials together
with your tool without stripping, splitting
or separating the material.
First, clamp the pieces together and drill
the first hole 2/3 the diam eter of the
screw. If the material is soft, drill only 2/3
the proper length. If it is hard, drill the
entire length.
Second, unclamp the pieces and drill the
second hole the same diameter as the
screw shank in the first or top piece of
wood.
Third, if flat head screw is used,
countersink the hole to make the screw
flush with the surface. Then, simply apply
even pressure when driving the screw. The
screw shank clearance hole in the first
piece allows the screw head to pull the
pieces tightly together.
▼ DRIVING NUTS AND BOLTS
Variable speed control must be used with
caution for driving nuts and bolts with
socket set attach ments. The technique is to
start slowly, increasing speed as the nut or
bolt runs down. Set the nut or bolt snugly
by slowing the drill to a stop. If this
procedure is not followed, the tool will
have a tendency to torque or twist in your
hands when the nut or bolt seats.
2. Drill same
diameter as
screw shank.
3. Countersink
same diameter
as screw head.
Screw