Stihl TS 440 Instruction Manual page 30

English
Short names
D-B10
The short name on a diamond cutting
wheel is a combination of letters and
numerals with up to four digits:
The letters indicate the authorized
–
use for the diamond cutting wheel.
The numerals indicate the
–
performance class of the STIHL
diamond cutting wheel.
Letter Authorized use
D-A Asphalt
D-B Concrete
BA Concrete, Asphalt
SB* Rock, Concrete
D-G Ductile iron
(*)
also can be used for structural steel
up to 10 mm thick and ductile iron –
not suitable for continuous cutting
of such materials
Radial and axial run-out
A correctly mounted spindle bearing on
the cut-off machine is essential for
normal service life and efficient
operation of the abrasive cutting wheel.
28
Using an abrasive cutting wheel on a
cut-off machine with an improper, worn
or damaged spindle bearing can lead to
axial and radial run-out.
Excessive radial run-out (A) overloads
individual diamond segments and
causes them to overheat. This can lead
to stress cracking in the wheel core or to
softening of individual segments. The
result can be broken segments that
increase the risk of personal injury.
Axial run-out or spindle wobble (B) also
results in higher thermal stresses and
wider cuts.
Undercut
Undercutting is a wearing away of the
steel core of the wheel at or just below
the diamond segments. When cutting
road surfaces, do not cut through into
the more abrasive ballast (gravel,
crushed rock) below the paved surface,
as indicated by a light colored dust.
Doing so can cause undercutting. If
undercutting can be detected upon
visual inspection, replace the wheel.
WARNING
Undercutting can result in wheel
breakage and/or thrown segments,
which can lead to severe personal injury
or death to the operator or bystanders.
Immediately replace a diamond cutting
wheel if undercutting is visible.
Built-up edges, dressing
Built-up edges are identified by a pale
grey deposit on the top of the diamond
segments that clogs and blunts the
segments.
Built-up edges can form:
when cutting extremely hard
–
material, such as granite,
as a result of incorrect handling,
–
such as applying excessive feed
force.
Built-up edges increase vibration,
reduce cutting performance and cause
sparking.
Diamond cutting wheels must be
"dressed" at the first sign of built-up
edges. To dress a diamond cutting
TS 440