Page 154 - Threading_Handbook

3
Thread Milling
THREAD MILLING ½

Today, thread milling is increasingly used to produce external and internal threads.
Some of the many advantages include:

• One tool is used for external and internal production and for right-and left-hand
threading in through or blind holes
• No need to change the tool for production of different thread diameters -
one tool is suitable for various thread milling diameters
• Thread length milling in one pass
• Short machining time

• Thread milling next to the bottom of blind hole
• Bottom thread relief not required
• Excellent and controlled thread surface finish
• Indexability and repeatability when changing or replacing cutter

• No problems with removing and replacing a broken tool: it is possible
to extract the broken tool without damaging the part

• Easy and efficient machining for thread milling in CNC milling machining centers
• Threading in asymmetric parts
• There is no limit to the size of the part where threading is required

ISCAR offers a wide range of cutter diameters for all types of threads.

The Principle of Thread Milling Production is Based on the Following:
The cutter is located parallel to the part axis along the required thread. The cutter rotates
around itself and enters into the part radially or tangentially until reaching the required
depth depending on the thread type. Simultaneously, rotary motion of the cutter around its
axis moves spirally along the whole length of the requested thread. The cutter movement
along the thread length while completing one round around the part is equal to the pitch
of requested thread. In this way, the threading is done while completing 1-1.3 turns of the
tool around the workpiece; 0.3 turn is necessary for a full plunge of the cutter to the thread
depth (at start thread production) and overlap the plunge location of cutting
(at end thread production).

154 ISCAR