On an LB, not for an LU, but I did some today. See below.
N2
G0 X20 Z20M5
T0202
TPI=18 (THREADS PER INCH)
TDIA=.625 (THREAD OD)
CDIA=.453 (CUTTER DIA)
ZSTR=0. (Z STARTING POINT)
ZSTP=-.562 (Z STOPPING POINT)
HPTC=[1/TPI]/2 (HALF PITCH)
M110
SB=4500 M14
Z.2
X0
M8
G1 G94 Z=ZSTR F20 M16
G91 C180 X[TDIA-CDIA] Z=-HPTC F100
NTHR
C180 Z-HPTC
V3=VSIOZ-HPTC
IF[VSIOZ-HPTC GT ZSTP]NTHR
C180 X-[TDIA-CDIA] Z-HPTC
G90
G0X0
Z.5
G0 G95 X2 M12
X20 Z20 M9 M109
M01