TS 440
English
28
Short names
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.
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.
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 
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