For example, in 316 stainless steel, a single-flute thread mill would take 40 to 45 seconds to thread a hole. “With the inserted cutter, you could only get possibly one insert in there so your cycle times would be slow. “In a lot of cases, when you get into holes ¾ ' and smaller you can still get a 4- or 6-flute solid cutter in there to do the job,” Hartford said. Smaller inserted thread mills are available but they usually have only one or two flutes. The inserted type with multiple flutes is typically for thread milling holes ¾ ' in diameter or larger because there has to be enough room for the tool body and inserts. Advent manufactures single- and multiple-flute inserted thread mills and solid-carbide thread mills. “Rarely do I run across someone who can’t do it,” noted Jim Hartford, vice president of Advent Tool & Manufacturing Inc., Antioch, Ill. The same KOMET JEL thread mill cutting two different diameter holes-an M10×1.5 (left) and an M18×1.5. Most CNC machines built in the last 10 to 15 years have this capability. Two axes perform circular interpolation while the third moves perpendicular to the circular plane. Thread milling requires a machining center capable of helical interpolation, which requires three axes of simultaneous movement. “In reality, we can set up a customer to successfully thread mill fairly easily-as long as they have the right tooling.” Sales - USA, Troy, Mich., which offers solid-carbide and indexable-insert thread mills. “Thread milling is not a big mystery, but some shops are hesitant to do it,” said Joe Mazzenga, sales manager for J.M. While thread milling is a well-established process, some machine shops are still afraid to try it, fearing it is too complicated.

Carmex thread mill chart