Sandvik Coromant Threading - Manual (Page 40)

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Z
Y
X
2. Applications – Thread milling
Tool path
Thread milling requires machine tools which are capable of simultane-
ous movements on the X, Y and Z axes. The thread diameter is deter-
mined by the X and Y axis, while pitch is controlled by the Z axis.
Right-hand internal threads
All cutters are initially positioned as close as possible to the bottom
of the hole, and then move anticlockwise in an upwards direction to
ensure that down milling is achieved.
Left-hand internal threads
Milling a left-hand thread follows in the opposite direction, from top to
bottom, also in an anticlockwise path to ensure that down milling is
achieved.
Internal External
Right-hand
threads Left-hand
threads Right-hand
threads Left-hand
threads
Down-milling Down-milling
Up-milling Up-milling
Pitch
First
choice
First
choice