CNC Machine Codes, Terms and Definitions

List of CNC Machine Codes, Terms and Definitions. Some of the codes, terms and definitions might be difference between manufactures for difference type of machine and machine controller.

A-axis = Capability of machining tools moving in circular motion around x-axis

B-axis = Capability of machining tools moving in circular motion around y-axis

C-axis = Capability of machining tools moving in circular motion around z-axis

X-axis = Capability of machine tools moving in the x-axis direction
Y-axis = Capability of machine tools moving in the y-axis direction
Z-axis = Capability of machine tools moving in the z-axis direction

D code = Tool diameter offset number
E code = Selection of work coordinate system. Equivalent to G54 to G59
F code = Feedrate
G code = A CNC program code that determines the type of operation to perform

H code = Tool length offset number
I code = Absolute center of arc in x-axis
J code = Absolute center of arc in y-axis
K code = Absolute center of arc in z-axis
L code = The number of repetition of a cycle
M code = The program code that control overall machine function
N code = Block number
O code = The program number allows you to identify your program with a certain number

P code = Parameter
Q code = Depth of cut parameter in canned drilling cycles
R code = Represent the radius, a return point or a general parameter
S code = Spindle speed
T code = Tool number
U code = Relative axis parallel to x-axis
V code = Relative axis parallel to y-axis
W code = Relative axis parallel to z-axis
X code = Absolute machine tool position on x-axis
Y code = Absolute machine tool position on y-axis
Z code = Absolute machine tool position on z-axis