12
English / USA
MSE 140 C, MSE 160 C, MSE 180 C, MSE 200 C
the powerful force used to cut wood can 
be reversed (and work against the 
operator). If the rotating chain is 
suddenly stopped by contact with any 
solid object like a log or branch or is 
pinched, the reactive forces may occur 
instantly. These reactive forces may 
result in loss of control which may, in 
turn, cause serious or fatal injury. An 
understanding of the causes of these 
reactive forces may help you avoid loss 
of control.
The most common reactive forces are
– kickback,
– pushback,
– pull-in.
Kickback:
Kickback may occur when 
the moving saw chain 
near the upper quadrant 
of the bar nose contacts a 
solid object or is pinched.
The reaction of the cutting force of the 
chain causes a rotational force on the 
chainsaw in the direction opposite to the 
chain movement. This may fling the bar 
up and back in an uncontrolled arc 
mainly in the plane of the bar. Under 
some cutting circumstances the bar 
moves towards the operator, who may 
suffer severe or fatal injury. 
Kickback may occur, for example, 
when the chain near the upper quadrant 
of the bar nose contacts the wood or is 
pinched during limbing or when it is 
incorrectly used to begin a plunge or 
boring cut.
The greater the force of the kickback 
reaction, the more difficult it becomes for 
the operator to control the saw. Many 
factors influence the occurrence and 
force of the kickback reaction. These 
include chain speed, the speed at which 
the bar and chain contact the object, the 
angle of contact, the condition of the 
chain and other factors. 
The type of bar and saw chain you use 
is an important factor in the occurrence 
and force of the kickback reaction. Some 
STIHL bar and chain types are designed 
to reduce kickback forces. STIHL 
recommends the use of reduced 
kickback bars and low kickback chains.
001BA093 LÄ
001BA035 KN