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8. PRECAUTIONS IN USAGE
8-1. Drilling with Diamond Core Bits
(1) Ensure that the Side Handle is firmly secured before
attempting to operate the tool. The side handle is
separated from the main body of the tool when it is shipped
from the factory. Carefully instruct the customer to loosen
the grip portion of the side handle by turning it as shown in
the right figure, install it on the gear cover portion, and fix it
securely in the desired position before operating the tool.
(2) Diamond core bits:
Diamond core bits applicable to the Model DC 120VA and DC 120V are dry-type diamond core bits for drilling
brick, concrete block and similar materials. Instruct the customer not to apply water during the drilling
operation. In addition, the customer should be advised that drilling may not be possible in bricks and blocks
which are particularly high in hardness and density.
(3) Rotation speed during drilling:
If you exceed the standard values (optimum speed of rotation) given in Table 1 in the Handling Instructions or
engage in continued work for an extended period of time or perform a drilling job on soft materials, the motor
may be subjected to an unreasonable load and may result in burnout. Especially, avoid any abnormal use
where the drill stops during the drilling work. Adjust the number of rotations so that a smooth drilling job can
be done at all times. Make absolutely certain that you never use any tool or bit beyond its maximum capacity
as otherwise the service life of the main unit may be extremely shortened.
Table 1
Side handle
Grip
Gear cover
Dial
1
[Low speed gear]
2
[High speed gear]
A
B
C
D
E
A
B
C
D
E
450 600 770 940 1050 850 1100 1400 1700 2000
No load
speed
(min
-1
)
Drill diameters
Shift lever indication
Materials to be drilled Types of drills
Brick, block
Autoclaved lightweight
concrete t3.0
Steel
SPCC t3.0
Stainless steel
t1.6
Wood
t50
Steel SPCC t3.0
Wood t50
Diamond
core bit
Hole saw
Hole saw
Hole saw
Hole saw
Drill
Drill
27
65
152
27
65
120
15
55
15
55
27
65
120
13
30
: Standard values (optimum speed of rotation)