TS 410, TS 420
English
12
power available for the actual cutting 
work. It could also damage the abrasive 
wheel.
STIHL recommends the use of the cart 
for longer cuts in a straight line.
Wet Cutting with Abrasive Wheels
Before wet cutting, make sure water will 
not damage the floor or building.
WARNING
To reduce the risk of electrocution to you 
or bystanders, do not allow water or 
sludge to contact live electric wires.
WARNING
To reduce the risk of injury from wheel 
breakage when wet cutting with any 
composite wheel:
1. Make certain water does not flow on 
a wheel that is not running, since the 
wheel will absorb water, which will 
affect wheel balance.
2. Be certain water is applied to both 
sides of wheel, since uneven 
distribution can cause "one sided" 
wear.
3. After finishing work, run the cutting 
wheel at normal operating speed for 
about 3 to 6 seconds without water 
so that the remaining water is flung 
off.
WARNING
To reduce the risk of injury from wheel 
breakage when wet cutting with a 
composite wheel that is not specifically 
designed for wet cutting, never store and 
reuse such a wheel that has been used 
with water. Use these wheels up the 
same day.
Reactive Forces including Kickback
WARNING
The powerful force used to cut through a 
workpiece can be reversed and work 
against the operator. If the wheel is 
slowed or stopped by frictional contact 
with any solid object or by a pinch or 
binding, reactive forces can occur 
instantly and may result in the operator 
losing control of the cut-off machine, 
which, in turn, may result in serious or 
fatal injury.
An understanding of the causes of these 
reactive forces may help you avoid loss 
of control. Reactive forces are exerted in 
a direction opposite to the direction in 
which the wheel is moving at the point of 
contact or of pinching/binding. If the 
wheel is slowed solely by frictional 
contact with a solid object, such as the 
workpiece, the resulting reactive forces 
are normally moderate and readily 
controllable by an operator who is 
holding the machine properly. If, 
however, the wheel is abruptly slowed or 
stopped by a pinch or severe bind, the 
reactive forces may be substantially 
greater. The greater the force 
generated, the more difficult it will be for 
the operator to control the cut-off 
machine. Loss of control can result in 
severe personal injury or death.
Pull-away, Climbing, Pinching and 
Rotational Kickback Forces
The most common reactive forces are 
pull-away and climbing. If the contact is 
at the bottom of the wheel, a cut-off 
machine will try to pull away from the 
operator (pull-away.) If the contact is at 
the front of the wheel, the wheel may 
attempt to climb the object being cut 
(climbing.)
Pinching occurs when the piece being 
cut closes on the wheel. A severe 
binding may also occur if the wheel is 
substantially sideloaded in the kerf or if 
an improper or damaged diamond wheel 
begins or ceases to wobble in the kerf. If 
the wheel is severely pinched or bound 
in the upper quadrant, the wheel may be 
instantly thrown up and back towards 
the operator with great force in a 
rotational kickback motion. Such 
kickback situations can and should 
always be avoided. Pinching of the 
wheel can be prevented by proper 
support of the workpiece. (See below.) 
Severe binding of the wheel can be 
prevented by proper cutting techniques, 
e.g., not sideloading the wheel, and by 
the use of properly designed, 
manufactured and maintained wheels.
Reactive forces may 
occur at any time the cut-
ting wheel on a cut-off 
machine is rotating.