Makita DHP451RTJ Instruction Manual Download Page 8

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Adjustable depth rod (Fig. 12)

The adjustable depth rod is used to drill holes of uniform
depth. Loosen the clamp screw, set to desired position,
then tighten the clamp screw.

Hook (Fig. 13)

The hook is convenient for temporarily hanging the tool.
This can be installed on either side of the tool.
To install the hook, insert it into a groove in the tool
housing on either side and then secure it with a screw. To
remove, loosen the screw and then take it out.

OPERATION

Hammer drilling operation

CAUTION:

• There is a tremendous and sudden twisting force

exerted on the tool/bit at the time of hole break-
through, when the hole becomes clogged with chips
and particles, or when striking reinforcing rods
embedded in the concrete. Always use the side grip
(auxiliary handle) and firmly hold the tool by both side
grip and switch handle during operations. Failure to do
so may result in the loss of control of the tool and
potentially severe injury.

First, slide the action mode change lever so that it points
to the marking. The adjusting ring can be aligned in any
torque levels for this operation.
Be sure to use a tungsten-carbide tipped bit. Position the
bit at the desired location for the hole, then pull the switch
trigger. Do not force the tool. Light pressure gives best
results. Keep the tool in position and prevent it from
slipping away from the hole.
Do not apply more pressure when the hole becomes
clogged with chips or particles. Instead, run the tool at an
idle, then remove the bit partially from the hole. By
repeating this several times, the hole will be cleaned out
and normal drilling may be resumed.

Blow-out bulb (optional accessory)

After drilling the hole, use the blow-out bulb to clean the
dust out of the hole.

Screwdriving operation (Fig. 14)

First, slide the action mode change lever so that it points
to the marking. Adjust the adjusting ring to the proper
torque level for your work. Then proceed as follows.
Place the point of the driver bit in the screw head and
apply pressure to the tool. Start the tool slowly and then
increase the speed gradually. Release the switch trigger
as soon as the clutch cuts in.

NOTE:

• Make sure that the driver bit is inserted straight in the

screw head, or the screw and/or bit may be damaged.

• When driving wood screws, predrill pilot holes to make

driving easier and to prevent splitting of the workpiece.
See the chart.

006405

NOTE:

• If the tool is operated continuously until the battery

cartridge has discharged, allow the tool to rest for
15 minutes before proceeding with a fresh battery.

Drilling operation

CAUTION:

• Pressing excessively on the tool will not speed up the

drilling. In fact, this excessive pressure will only serve
to damage the tip of your bit, decrease the tool
performance and shorten the service life of the tool.

• There is a tremendous force exerted on the tool/bit at

the time of hole break through. Hold the tool firmly and
exert care when the bit begins to break through the
workpiece.

• A stuck bit can be removed simply by setting the

reversing switch to reverse rotation in order to back
out. However, the tool may back out abruptly if you do
not hold it firmly.

• Always secure small workpieces in a vise or similar

hold-down device.

• If the tool is operated continuously until the battery

cartridge has discharged, allow the tool to rest for
15 minutes before proceeding with a fresh battery.

First, slide the action mode change lever so that it points
to the marking.
The adjusting ring can be aligned in any torque levels for
this operation. Then proceed as follows.

Drilling in wood

When drilling in wood, the best results are obtained with
wood drills equipped with a guide screw. The guide screw
makes drilling easier by pulling the bit into the workpiece.

Drilling in metal

To prevent the bit from slipping when starting a hole,
make an indentation with a center-punch and hammer at
the point to be drilled. Place the point of the bit in the
indentation and start drilling.
Use a cutting lubricant when drilling metals. The
exceptions are iron and brass which should be drilled dry.

MAINTENANCE

CAUTION:

• Always be sure that the tool is switched off and the

battery cartridge is removed before attempting to
perform inspection or maintenance.

Nominal diameter of wood

screw (mm)

Recommended size of pilot

hole (mm)

3.1

2.0 - 2.2

3.5 2.2

2.5