Bone Screws

Over the past several years we have seen the whirling process come of age, so to speak. This very efficient and fast method of producing threads has recently been integrated into swiss type screw machines. This combining of operations goes against the "lean" ideals of high productivity by performing as many operations in a single machine. It is the philosophy of Leistritz, arguably the most renown and experienced machine builder in the field of whirling, that separating operations is more productive! The very features that make swiss-type turning centers unbeatable for turning small diameter and long shafts, screws or spindles are exactly what make them less efficient whirling machines. Feeding of the bar material through a guide collet has the disadvantage of not permitting continuous rough and finish turning over a long length, so whirling a long screw requires incremental turning and whirling steps until the whole screw length is achieved or whirling the screw without turning the blank to the thread major diameter first! Both of these alternatives are not only time consuming but inaccurate as well.
The Leistritz concept is to turn bone screws blanks in existing swiss-type turning centers without the thread. This would allow an even shorter cycle time and greater throughput per machine. Then, with a whirling only machine, whirl the thread. Leistritz whirling machines have the necessary following supports to permit whirling of screws with any profile in virtually unlimited lengths in the shortest possible time. Whirling by Leistritz can outperform whirling in a turning center by a factor of 2 or possible 3:1! Most Bone Screws even in their longest designs and in either 316L stainless steel or Titanium are whirled in under 60 seconds!