(cut a small 1/4-20 thread and part it)
(t1 is for facing and left turning, t4 is threading tool, t9 parting)
(proper tool offsets should be set in the tool table!)

g20 g64 g18

(face and turn outside diameter)
t1 m6
s1200 m3
g4p1
g43
g0z0x.2
f4
g1x-.0625
g0z.1
x.120
f5
g1z-.55
g0x.2


(round the end)
o100 sub 
g0z1x-1
g41
g0z1
g2 x0 z0 r1
g3 x3.05 z-3.05 i0 k-3.05
g91 
g2 z-1.5 x1 r1.5
g90 
g40
g0 x4.5
o100 endsub

g21
f50

g0z1.3
g92z0
o100 call

f50

g92.1
g0z.9
g92z0
o100 call

g92.1
g0z.5
g92z0
o100 call

g92.1
g0z.3
g92z0
o100 call

g92.1
g0z.1
g92z0
o100 call

g92.1
g0z0
g92z0
o100 call
g0z0
o100 call

g92.1
g0z-.025
g92z0
o100 call

g92.1
m5
g20
f5

(thread)
t4 m6
g43
s800 m3
g4p1
g0z.2x.2

(p = thread pitch, distance per revolution)
(z = end of drive line)
(i = offset from drive line to thread peaks)
(    negative i means the threads are at a smaller radius than the drive line,)
(    so i is negative for outside threads, positive for inside threads)
(j = initial cut depth; subsequent depths follow degression formula)
(r = depth degression: 1.0 = constant depth, 2.0 = constant area)
(                      any number >= 1.0 allowed)
(k = full thread depth)
(q = "compound slide" angle)
(h = number of spring passes)
(e = distance along drive line used for tapered start/end)
(l = which ends get the taper: 0 = neither, 1 = begin, 2 = end, 3 = both)
g76 p.05 z-.5 i-.075 j.008 k.045 h3 r2.0 q29.5 e.05 l2
g0x.5
g0z0
m5

(part)
t9 m6
g43 
s400 m3
g4p1
g0z-.6x.135
g1x0f.2
g0x.2
m2