Circular Saw Safety Warnings - Hitachi C7ST Handling Instructions Manual

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CIRCULAR SAW SAFETY WARNINGS

Cutting procedures
a) DANGER: Keep hands away from cutting area
and the blade. Keep your second hand on auxiliary
handle, or motor housing.
If both hands are holding the saw, they cannot be
cut by the blade.
b) Do not reach underneath the workpiece.
The guard cannot protect you from the blade below
the workpiece.
c) Adjust the cutting depth to the thickness of the
workpiece.
Less than a full tooth of the blade teeth should be
visible below the workpiece.
d) Never hold piece being cut in your hands or across
your leg. Secure the workpiece to a stable platform.
It is important to support the work properly to
minimize body exposure, blade binding, or loss of
control.
e) Hold the power tool by insulated gripping surfaces
only, when performing an operation where the
cutting tool may contact hidden wiring or its own
cord.
Contact with a "live" wire will also make exposed
metal parts of the power tool "live" and could give
the operator an electric shock.
f) When ripping always use a rip fence or straight
edge guide.
This improves the accuracy of cut and reduces the
chance of blade binding.
g) Always use blades with correct size and shape
(diamond versus round) of arbour holes.
Blades that do not match the mounting hardware
of the saw will run eccentrically, causing loss of
control.
h) Never use damaged or incorrect blade washers or
bolt.
The blade washers and bolt were specially designed
for your saw, for optimum performance and safety
of operation.
Kickback causes and related warnings
– kickback is a sudden reaction to a pinched, bound
or misaligned saw blade, causing an uncontrolled saw
to lift up and out of the workpiece toward the operator;
– when the blade is pinched or bound tightly by the kerf
closing down, the blade stalls and the motor reaction
drives the unit rapidly back toward the operator;
– if the blade becomes twisted or misaligned in the cut,
the teeth at the back edge of the blade can dig into
the top surface of the wood causing the blade to climb
out of the kerf and jump back toward the operator.
Kickback is the result of saw misuse and/or incorrect
operating procedures or conditions and can be avoided
by taking proper precautions as given below.
a) Maintain a firm grip with both hands on the saw
and position your arms to resist kickback forces.
Position your body to either side of the blade, but
not in line with the blade.
Kickback could cause the saw to jump backwards,
but kickback forces can be controlled by the operator,
if proper precautions are taken.
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b) When blade is binding, or when interrupting a cut
for any reason, release the trigger and hold the saw
motionless in the material until the blade comes
to a complete stop.
Never attempt to remove the saw from the work
or pull the saw backward while the blade is in
motion or kickback may occur.
Investigate and take corrective actions to eliminate
the cause of blade binding.
c) When restarting a saw in the workpiece, centre
the saw blade in the kerf and check that saw teeth
are not engaged into the material.
If saw blade is binding, it may walk up or kickback
from the workpiece as the saw is restarted.
d) Support large panels to minimise the risk of blade
pinching and kickback.
Large panels tend to sag under their own weight.
Supports must be placed under the panel on both
sides, near the line of cut and near the edge of the
panel.
e) Do not use dull or damaged blades.
Unsharpened or improperly set blades produce
narrow kerf causing excessive friction, blade binding
and kickback.
f) Blade depth and bevel adjusting locking levers must
be tight and secure before making cut.
If blade adjustment shifts while cutting, it may
cause binding and kickback.
g) Use extra caution when sawing into existing walls
or other blind areas.
The protruding blade may cut objects that can cause
kickback.
Lower guard function
a) Check lower guard for proper closing before each
use. Do not operate the saw if lower guard does
not move freely and close instantly. Never clamp
or tie the lower guard into the open position.
If saw is accidentally dropped, lower guard may be
bent.
Raise the lower guard with the retracting handle
and make sure it moves freely and does not touch
the blade or any other part, in all angles and depths
of cut.
b) Check the operation of the lower guard spring. If
the guard and the spring are not operating
properly, they must be serviced before use.
Lower guard may operate sluggishly due to damaged
parts, gummy deposits, or a build-up of debris.
c) Lower guard may be retracted manually only for
special cuts such as "plunge cuts" and "compound
cuts".
Raise lower guard by retracting handle and as soon
as blade enters the material, the lower guard must
be released.
For all other sawing, the lower guard should operate
automatically.
d) Always observe that the lower guard is covering
the blade before placing saw down on bench or
floor.
An unprotected, coasting blade will cause the saw
to walk backwards, cutting whatever is in its path.
Be aware of the time it takes for the blade to stop
after switch is released.