16
the socket and anvil. Then return the O-ring to
the original position in the socket groove to re-
tain the pin. To remove the socket, follow the
installation procedures in reverse.
TORQUE
The tightening torque depends on the dura-
tion of the impacting/tightening action.
The largest tightening torque is achieved after
approx. 3 to 5 sec. 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 surface of the junction.
WARNING: Hold the tool firmly. The torque
force may hurt you.
OPERATION INSTRUCTIONS
1. Be sure the rotational direction is “Forward”.
2. Start the fastener by hand onto or into its
threaded counter part (e.g. nut onto bolt,
screw into nut or threaded hole).
3. With the proper impact socket securely
mounted to the wrench, slide the impact sock-
et onto the nut or bolt head.
4. Hold the tool securely with both hands and
squeeze the trigger switch. The impact socket
will turn the fastener and impacting will begin
once the fastener encounters resistance.
WARNING: Do not
over tighten, as the
force of the Impact
Wrench can break the
fastener. Keep the Im-
pact Wrench at a right
angle to the fastener
to avoid damaging
the fastener head.
NOTE: The proper fastening torque may differ
depending upon the kind or size of the bolt,
the material of the workpiece to be fastened,
etc. The relation between fastening torque
and fastening time is shown in the figures.
NOTE:
• Hold the tool pointed straight at the bolt or
nut.
• Excessive fastening torque may damage the
bolt/nut or socket. Before starting your job,
always perform a test operation to determine
the proper fastening time for your bolt or nut.
• 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 cartridge. The fastening
torque is affected by a wide variety of factors
including the following. After fastening, al-
ways check the torque with a torque wrench.
1. When the battery cartridge is discharged
almost completely, voltage will drop and the
fastening torque will be reduced.
2. Socket; Failure to use the correct size socket
will cause a reduction in the fastening torque.
• A worn socket (wear on the hex end or
square end) will cause a reduction in the fas-
tening torque.
3. Bolt; Even though the torque coefficient and
the class of bolt are the same, the proper fas-
LI920A
LI1020
LI920A-LI1020 manual.indd 16
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