Operator`s manual

Advanced Haas Mill Programming Techniques Training Manual Page 56
OD Thread Milling
In vertical machining centers tapping is the predominant method of creating threads. In some situations
however it is difficult or impractical to use taps. In these instances thread milling may be the only way to
create threads. A thread mill is a cutter formed with the pitch of the thread desired. Solid carbide cutters
are fragile and expensive. Internal holes smaller than 3/8” may not possible or practical to create using
solid carbide thread mills. For large threads, external threads, port threads, blind holes thread milling can
be the most economical method. Climb cutting is generally used for better tool life.
Common uses of Thread Milling:
Large diameter threads: Any size thread may be created using thread milling.
Some machines lack the power at low RPM’s to push large taps through.
Taps are not available in a particular size.
Tapping is difficult because of blind holes or hard material.
Left hand taps unavailable.
Longer tool life with thread mills.
Better surface finish with thread mills.
Easier or no thread deburring required.
One tool accepts inserts of different pitch sizes.
Cost reductions.
Thread Milling Tools (Examples taken from Carmex Precision Tools Ltd. X-Extreme Thread Cutting
Catalog, Inch 2013, Carmex Precision Tools LLC, 2075 Hwy 175, Richfield, WI 53076)
Carmex Twin Insert Mill Thread Tool Holder