909 T12ID4 Instruction Manual - Tightening Torque
6
INSERTING A DRIvER OR NUT SETTER bIT
INTO THE ImPACT DRIvER ATTACHmENT
WARNING!
Do not insert or remove bits while the tool is
activated. Make sure the battery pack is removed or the tool is in
sleep mode when inserting or removing bits.
1. Your tool is equipped with a quick release
chuck. To insert an accessory, simply
pull the locking sleeve forward, insert the
desired accessory fully into the chuck and
release the locking sleeve.
(Fig G)
2. To remove an accessory, pull the locking
sleeve forward and simply remove the
accessory from the chuck.
3. To avoid loss of control, ensure the bit is locked into the chuck by
pulling on the bit after it has been inserted and the locking sleeve
released.
The technique is to start slowly, increasing the speed as the screw
runs down. Set the screws snugly by slowing to a stop. Prior to
driving screws, the right impacting/tightening duration can be
reached in less than 0.5 seconds. Therefore, work with low RPM and
switch the machine off immediately when the screw is tight and the
impacting sound is 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. 6 to 10 seconds 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 relatively short impacting/
tightening action.
Medium case:
The joining of metal to metal where the 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 than for hard cases. Therefore, a longer impacting/tightening
action is necessary to arrive at the maximum tightening torque.
FASTENING wITH SCREwS
This procedure will enable you to fasten materials together with your
tool without stripping, splitting or separating the material
(fig I)
Note:
Always use a test piece to determine the correct time to allow
the impact driver to impact. The longer the impact time when seating
the screw, the higher the torque being applied. Small screws can
easily strip or shear if over tightened.
The following is a guide but application will vary between screws
and materials being screwed together.
The most IMPORTANT point is to learn the impact time when seating
the screw.
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.
I
G