Instruction Manual

0458-787-8621-A
21
English 6 Kickback and Other Reactive Forces
location and angle of contact, the condition of the chain,
and how quickly the chain is slowed or stopped, among
other factors.
– The type of bar and 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.
6.2.2 Chain Saw Kickback Standards
The following standards apply with respect to kickback:
– § 5.11 of ANSI/OPEI B175.1
This standard, referred to as "the chain saw kickback
standard" in this chapter, sets certain performance and
design criteria related to chain saw kickback.
To comply with the chain saw kickback standard:
a)Chain saws with a displacement of less than 3.8 cu. in.
(62 cm³):
– must, in their original condition, meet a 45° computer-
derived kickback angle when equipped with certain
cutting attachments; and
– must be equipped with at least two devices to reduce
the risk of kickback injury, such as a chain brake, low
kickback chain, reduced kickback bar, etc.
b)Chain saws with a displacement of 3.8 cu. in. (62 cm³) and
above:
– must be equipped with at least one device designed to
reduce the risk of kickback injury, such as a chain brake,
low kickback chain, reduced kickback bar, etc.
The computer derived angles for chain saws below
3.8 cu. in. (62 cm³) displacement are measured by applying
a computer program to test results from a kickback test
machine.
WARNING
￭ Compliance with the chain saw kickback standards does
not mean that the bar and chain will rotate at most 45° in
a real life kickback.
￭ The computer-derived angles of the chain saw standards
may bear no relationship to actual kickback bar rotation
angles that may occur in a real life cutting situation.
￭ Devices designed to reduce the risk of kickback injuries
may lose some of their effectiveness when they are no
longer in their original condition, especially if they have
been improperly maintained.
– Read and follow the safety precautions and
instructions in this manual.
– When working, always position the chain saw such
that your body is clear of the cutting attachment and
outside of the cutting plane.
– Follow the maintenance and service instructions in
this manual.
￭ For the chain saw to meet the chain saw kickback
standards, use only the following cutting attachments:
– Compliant bar and chain combinations listed in
"Combinations of Guide Bars and Saw Chains,"
@ 26;
– Other replacement bar and chain combinations
marked in accordance with the standards for use on
the chain saw; or
– Replacement chain designated "low kickback chain."
6.2.3 Devices for Reducing the Risk of Kickback Injury
The STIHL Quickstop chain brake and STIHL's green-
labeled, reduced kickback bars and green-labeled, low
kickback chains are designed to reduce the risk of kickback
injury.