CNC G92 threading cycle for fanuc program (metric threading)

G92 threading code is used in "G-code system A"

O1571
N10   M06 T02 02 ;
N20   G50 S1500 ;
N30   M03 G97 S200 ;
N40   M08 ;
N50   G00 X50 Z2 ;
N60   G92 X49.07 Z-20 F1.5 ;
N70   X48.77
N80   X48.47
N90   X48.17 
N100 G28 U0 W0 ;
N110 M05 M09 M30 ;
                                                                              More examples..........!!!!
DESCRIPTION OF MAIN PROGRAM :-
Calculation :- Depth of thread = 0.6134 X Pitch
                                                 = 0.9201
                                        Crest = major dia - 0.9201
                                                 = 49.07
                                          Root = Major dia - 2 x Depth of thread
                                                   = 50 - 2 x 0.9201
                                                   = 48.16 (root)
Each cut is 150 microns =0.15mm , it means total reduce 0.30 mm and cutting upto root 48.16 mm
First cut is 49.07 mm (Crest)
Second cut is 49.07-0.3 = 48.77
Third cut is 48.77-0.3 = 48.47
Final cut is 48.47 -0.3 = 48.17 (~ 48.16)(root)
*************************all dimension in mm ***********************************
01571 - Name of main program
N10- Tool change command , select tool no 2
N20- Maximum spindle speed command , speed is 1500 rpm
N30- Spindle ON clockwise , constant spindle speed , speed is 200 rpm
N40- Coolant ON
N50- Rapid action command , where X50 and Z2 .

N60- Threading cycle command , where X49.07( crest )(First cut) and Z-20 , feed rate is 1.5 ( it is always is equal to pitch )

N70-  Second cut is  48.77 in X axis

N80- Third cut is 48.47 in X axis 

N90 - Final cut is 48.17 in X axis (root)

N100 - Reference position command , where X0 and Z0 ;

N110 - Spindle OFF , coolant OFF , main prog. end