Here you go:
O0000( T )
(PROGRAM NOTES)
(X = 0 AT )
(Y = 0 AT )
(Z = 0 AT )
(NOTES : )
(TOOLS LIST)
( T1 | .370 DIAM X 1 MM PITCH THREAD MILL | H1 | D1 | WEAR COMP | TOOL DIA. - .37 )
G20
G0 G17 G40 G49 G80 G90
( .370 DIAM X 1 MM PITCH THREAD MILL | TOOL - 1 | DIA. OFF. - 1 | LEN. - 1 | TOOL DIA. - .37 )
( THREAD 16 X 1.00 ID LEFT HAND THREAD )
T1 M6
G0 G90 G54 X0. Y0. S1200 M3
G43 H1 Z1.
M8
Z.1
G1 Z-.23 F50.
G42 D1 Y.05 F10.
G2 X.0375 Y.0625 Z-.2272 I.0375 J-.05
X.1 Y0. Z-.2202 I0. J-.0625
X0. Y-.1 Z-.2104 I-.1 J0.
X-.1 Y0. Z-.2005 I0. J.1
X0. Y.1 Z-.1906 I.1 J0.
X.1 Y0. Z-.1808 I0. J-.1
X.0375 Y-.0625 Z-.1738 I-.0625 J0.
X0. Y-.05 Z-.1709 I0. J.0625
G1 G40 Y0.
Z-.23 F50.
G42 D1 Y.075 F10.
G2 X.04 Y.085 Z-.2277 I.04 J-.075
X.125 Y0. Z-.2202 I0. J-.085
X0. Y-.125 Z-.2104 I-.125 J0.
X-.125 Y0. Z-.2005 I0. J.125
X0. Y.125 Z-.1906 I.125 J0.
X.125 Y0. Z-.1808 I0. J-.125
X.04 Y-.085 Z-.1733 I-.085 J0.
X0. Y-.075 Z-.1709 I0. J.085
G1 G40 Y0.
Z-.23 F50.
G42 D1 Y.0775 F10.
G2 X.0402 Y.0873 Z-.2277 I.0402 J-.0775
X.1275 Y0. Z-.2202 I0. J-.0873
X0. Y-.1275 Z-.2104 I-.1275 J0.
X-.1275 Y0. Z-.2005 I0. J.1275
X0. Y.1275 Z-.1906 I.1275 J0.
X.1275 Y0. Z-.1808 I0. J-.1275
X.0402 Y-.0873 Z-.1732 I-.0873 J0.
X0. Y-.0775 Z-.1709 I0. J.0873
G1 G40 Y0.
Z-.23 F50.
G42 D1 Y.08 F10.
G2 X.0404 Y.0896 Z-.2278 I.0404 J-.08
X.13 Y0. Z-.2202 I0. J-.0896
X0. Y-.13 Z-.2104 I-.13 J0.
X-.13 Y0. Z-.2005 I0. J.13
X0. Y.13 Z-.1906 I.13 J0.
X.13 Y0. Z-.1808 I0. J-.13
X.0404 Y-.0896 Z-.1732 I-.0896 J0.
X0. Y-.08 Z-.1709 I0. J.0896
G1 G40 Y0.
Z-.23 F50.
G42 D1 Y.08 F10.
G2 X.0404 Y.0896 Z-.2278 I.0404 J-.08
X.13 Y0. Z-.2202 I0. J-.0896
X0. Y-.13 Z-.2104 I-.13 J0.
X-.13 Y0. Z-.2005 I0. J.13
X0. Y.13 Z-.1906 I.13 J0.
X.13 Y0. Z-.1808 I0. J-.13
X.0404 Y-.0896 Z-.1732 I-.0896 J0.
X0. Y-.08 Z-.1709 I0. J.0896
G1 G40 Y0.
G0 Z.1
Z1.
M5
G91 G28 Z0. M9
G28 Y0.
M30
This is for a M16 x 1.0 Left hand Id thread, positioned at X0., Y0. it makes 2 rough passes @ .03 per side ea, 2 semifinish @ .005 and 1 spring pass, just in case lol! Since this thread is positioned at origin, you should be fine but adding/subtracting your hole position's for it on X & Y accordingly. Or just send them back
HTH.