
13. FUNCTIONS TO SIMPLIFY
PROGRAMMING B–63522EN/02
NC FUNCTION
166
A thread cutting cycle as shown below can be made.
W
C
(F)
(R)
A
U/2
∆d
E
i
X
Z
r
D
k
B
(R)
R : Rapid traverse
F : Cutting feed
G76 P(m)(r)(a) Q(∆d min) R(d) ;
G76 X_ Z_ R(i) P(k) Q(∆d) F(ȏ) ;
m : Number of final finishing repeats 1 to 99
r : Screw finishing (chamfering amount)
a : Tool tip angle (thread angle)
One of the six angles, 80°, 60°, 55°, 30°, 29°, and 0°, can
be selected as a 2-digit number. m, r, and a are specified in
address P at the same time.
Example)
When m = 2, r = 1.2ȏ, and a = 60 , they are specified as follows:
∆bmin: Minimum depth of cut
d : Finishing allowance
i : Difference in thread radius
Straight threading for i = 0
k : Height of the thread (The distance in X-axis direction is
specified with a radius value.)
∆d : Depth of first cut (specified with a radius value)
ȏ : Screw lead (same as threading of G32)
X_ Z_
U_W_
P02
m
12
r
60
a
13.5.7
Thread Cutting Cycle
(G76)
Format