For longer than most of us remember, long-reach machining has brought headaches to manufacturers.  That’s the bad news.

The good news is that recent tooling innovations ease the pain over a wide range of applications.  Today you can have a stable contour milling operation 22 inches deep inside a hardened steel mold cavity or stainless steel turbine bucket.  Today you can open large holes deep down between the webs in steel castings, and face-mill deeply recessed flats in iron castings – 3 to 5 times faster than before, with none of the usual chatter, much less risk of sudden tool rupture. 

There’s more.  Today, medical device manufacturers have a stable process for boring 4:1 aspect holes in thin-walled titanium — an application that has stymied conventional boring tools for more than a decade. 

And today, alert plastics fabricators are routing out deep recesses in their moldings twice as fast.

“No single tool meets all such diverse long-reach challenges, but those that do usually share two common features: high-feed insert geometries and extra-rigid shanks and extensions,” said Konrad Forman, North American milling product manager for Ingersoll Cutting Tools.  “That said, the right choice for a particular long-reach application would hinge mainly on the geometry of the cut to be made.”

By and large, high-feed insert geometries cut faster while reducing lateral cutting forces that can trigger chatter leading to sudden tool failure.  More rigid shanks reduce both chatter and runout all the way to the bottom of the cut.