Precautions For Use Of "Rotation Only" (No Striking) Function; Drill Bits - Hitachi DH 14DL Technical Data And Service Manual

4. Precautions for use of "Rotation only" (no striking) function

Each of the Models DH 14DL, DH 14DMR, DH 18DL and DH 18DMR is equipped with a change lever for
changeover between "rotation only" and "rotation and hammering" functions. Be sure to set the change
lever to "rotation only" for drilling into wood or metal materials or for driving screws by means of the optional
chuck adapter or drill chuck. Should the change lever be set to "rotation and hammering" when such an
optional tool is used for drilling or driving screws, the hammering action may cause the drill chuck or other
optional tool to be broken or damaged. Salespersons should carefully ensure that the buyer is thoroughly
advised on this point.

5. Drill bits

The chuck section is designed exclusively for the popular and widely available SDS-plus shank bits, as
shown in Fig. 2. Rotating torque is transmitted to the drill bit by two key rails provided in the tool holding
section. A steel ball is used to prevent the bit from falling out.
Fig. 2
Shape of the SDS-plus shank bit
Key slot
Key rail (2 pcs.)
Cylinder
Section AA
Ball holder
Steel ball
Sectional view of chuck section
The service life of a drill bit with a diameter of 8 mm is approximately 300 holes when drilling into concrete
with a depth of 30 mm. If reground before the end of its service life, the drill bit will continue to provide
efficient drilling. Figure 3 shows the regrinding angle.
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