Bone screws are the most common general purpose fixation devices. They may be the only hardware used in reparative or reconstruction surgery.
More commonly, they are used with other hardware devices, particularly plates, to fixate the associated device to bone.
Facts and component characteristics
The bone screw bar (diameter commonly 4 – 12 mm (0.157– 0.472 inch) is usually made of titanium (Ti6Al4V ELI) or stainless steel (316LVM).
- Long slender components, many different sizes
- Fixturing is a challenge in subspindel
- Batch production generally from 30 up to 1000
- Thread machined by whirling. Critical operation
For machining the bone screw, a sliding head machine, equipped with Sandvik Coromant CoroMill® 325
whirling system, a dedicated whirling unit and preferably a High Pressure Coolant pump with filter is used.
The thread of the bone screw is machined in a productive and secure process, resulting in good surface finish and good dimensional accuracy.
When machining the head of the screw, good chip control in a secure process is achieved.