Tightening Torque; Operating Tips - Bosch 24618 Consignes De Fonctionnement/Sécurité

BM 2610027761 08-12_BM 2610027761 08-12.qxp 8/17/12 1:54 PM Page 15
You will extend the life of your bits and do
neater work if you always put the bit in contact
with the work before pulling the trigger. During
the operation, 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
snugly by slowing to a stop. Prior to driving
screws, pilot and clearance holes should be
drilled.
Always hold the machine 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
impacting/tightening duration can be reached
in less then 0.5 Sec. Therefore, work with low
RPM and switch the machine 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

(Models 24618 & IWH181 only)
The tightening torque depends on the duration
of the impacting/tightening action. The largest
tightening torque is achieved after approx. 6 to
FASTENING WITH SCREWS
This procedure shown in (Fig. 9) will enable
you to fasten materials together with your tool
without stripping, splitting or separating the
material.
First, clamp the pieces together and drill the
first hole 2/3 the diameter 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.

Operating Tips

screws, the right
-15-
10 Sec. 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 case: The joining of metal to metal with a
disk washer. The maximum torque is reached
after a relative short impacting/tightening
action.
Medium case: The joining of metal to metal
where spring ring washer, disk spring washer,
stud bolts or bolts/nuts with conical seats are
used.
Soft case: The joining of e.g. metal to wood or
insulation material.
For middle or soft joining cases, the maximum
tightening torque is less as for hard cases.
Therefore, a longer impacting/tightening action
is necessary to arrive at the maximum
tightening torque.
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.
FIG. 9
2. Drill same
diameter as
screw shank.
3. Countersink
same diameter
as screw head.
Screw