Specifications
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 CONCISE GUIDE FANUC 129 
7.12 G41 G42 G40 MILLING RADIUS OFFSET IN G112 
Also in milling, as for turning, the tool radius offset can be used . 
To do so, it is necessary to enter in the tool table the cutter radius (R) and the tool orientation (T), The 
value of this orientation can be either T0 or T9 (for the procedure to enter this data see the Concise  
Guide for Operator ). 
It is also necessary to insert in the program functions G41 or G42 to activate the offset and  G40 for the 
deactivation. 
Functions G41 and G42 are used to define the position of the cutter as to the workpiece: 
    G41 => Workpiece on RIGHT of cutter 
    G42 => Workpiece on LEFT of cutter 
Function G40 DEACTIVATES the milling radius offset, with this function active, the described profile is 
travelled from the cutter centre. 
NOTE: It is recommended to activate (G41 or G42) and deactivate (G40) the milling radius offset at a 
distance greater that the value of the radius of the cutter used. 
It is best to start and interrupt the work with milling radius offset not at the exact point of the beginning of 
the work, but on an extension of the profile. 










