Sandvik Coromant Heat resistant super alloys - Manual (Page 113)

111
CoroMill®Plura
Threads are milled in one pass and this multi-point tool gives a
true full-profile thread form, with 60° metric, UNC/UNF and NPT/
NPTF options available.
Designed for smaller thread sizes and in two optimized grade
choices, with or without through coolant. Ideal tool for mass pro-
duction.
Multi-point threading
CoroMill®328
For larger holes over 39 mm, CoroMill 328 offers inserts for metric
and UN threads. Inserts are pocket-mounted for safe and stable
positioning, with 3 cutting edges per insert and high-pitch cutter
bodies. CoroMill 328 is available in versatile grade GC1025, for all
material types.
CoroMill 328 has Weldon, arbor and bore with keyway mounting.
Main considerations
To achieve the best results in a thread milling operation, always consider the following
points.
Choice of cutting diameter:
•
A smaller cutting diameter will help to achieve higher quality threads.
Tool path is important:
•
Tool path will give right or left hand threads, using down- or upmilling.
• Always engage and retract the thread mill in a smooth path, i.e. roll in and out of cut.
Be aware of feed per tooth:
•
Always work with small feed per tooth values (very small hex) to achieve best quality.
Always calculate the correct feed required by the machine software:
•
To ensure the correct insert load.
Several infeed passes may be needed:
•
In difficult applications, it may be necessary to separate the operation into several
infeed passes to achieve higher quality threads.
Note. Detailed information about thread milling is provided in the Threading application guide, C-2920:031. Contact
your local Sandvik Coromant representative for more information.