Maintenance And Inspection - Hitachi WH 14DCL Handling Instructions Manual

English
4. Work at a tightening torque suitable for the bolt under impact
The optimum tightening torque for nuts or bolts diff ers with material and size of the nuts
or bolts. An excessively large tightening torque for a small bolt may stretch or break the
bolt. The tightening torque increases in proportion to the operation time. Use the correct
operating time for the bolt.
5. Confi rm the tightening torque
The following factors contribute to a reduction of the tightening torque. So confi rm the
actual tightening torque needed by screwing up some bolts before the job with a hand
torque wrench. Factors aff ecting the tightening torque are as follows.
(1) Voltage
When the discharge margin is reached, voltage decreases and tightening torque is
lowered.
(2) Operating time
The tightening torque increases when the operating time increases. But the tightening
torque does not increase above a certain value even if the tool is driven for a long time.
(3) Diameter of bolt
The tightening torque diff ers with the diameter of the bolt. Generally a larger diameter bolt
requires larger tightening torque.
(4) Tightening conditions
The tightening torque diff ers according to the torque ratio; class, and length of bolts
even when bolts with the same size threads are used. The tightening torque also diff ers
according to the condition of the surface of workpiece through which the bolts are to be
tightened. When the bolt and nut turn together, torque is greatly reduced.

MAINTENANCE AND INSPECTION

1. Inspecting the driver bit
Using a broken bit or one with a worn out tip is dangerous because the bit can slip. Replace
it.
2. Inspecting the mounting screws
Regularly inspect all mounting screws and ensure that they are properly tightened. Should
any of the screws be loose, retighten them immediately. Failure to do so could result in
serious hazard.
3. Maintenance of the motor
The motor unit winding is the very "heart" of the power tool.
Exercise due care to ensure the winding does not become damaged and/or wet with oil or
water.
4. Cleaning of the outside
When the angle impact driver is stained, wipe with a soft dry cloth or a cloth moistened with
soapy water. Do not use chloric solvents, gasoline or paint thinner, for they melt plastics.
5. Storage
Store the angle impact driver in a place in which the temperature is less than 40°C, and out
of reach of children.
28