Sandvik Coromant aims CoroMill 325 threading whirling technology at sliding-head users supplying medical market
1 min read
Sandvik Coromant's CoroMill 325 thread whirling inserts and holders are designed for bone screw, spinal screw, implants and other medical device production. They are designed to thread long, slender components from rough stock at high speeds when mass-producing threaded medical components on sliding head machines such as Citizen, Star, Tsugami and Tornos.
Thread whirling is preferred to conventional single-point threading techniques due to its speed – the smooth, tangential cutting action minimises cutting forces to give high metal removal rates. This, in combination with the rigidity of a sliding head machine, results in precisely completed threads in a single pass.
These CoroMill 325 inserts from Sandvik Coromant can be quickly and easily mounted in the ring holders. Once complete, the user only has to insert the ring over the spindle screw, turn the ring anti-clockwise to the bottom position, and tighten the ring screw. To begin cutting, the spindle unit is tilted in relation to the desired helix angle of the screw and the ring is programmed off-centre (in relation to the thread diameter). For optimum tool life, the whirling ring and component should rotate in the same direction (climb milling).
With their strong cutting edges, inserts in the whirling ring apply even cutting pressure to create precision threads without bending the typically long and slender parts. Furthermore, chip control is superior to single-point threading, enabling more continuous and productive machining. Deeper thread forms such as Acme threads are also achieved more easily.
Standard inserts for HA and HB threads fit all CoroMill 325 whirling rings and follow thread standard ISO 5835-1991 for medical screws. Inserts for other thread forms can be ordered from Sandvik Coromant's non-standard range. All Sandvik Coromant thread whirling inserts are available in GC1105 – the first-choice grade for medical machining. GC1105 offers sharper edges and a burr-free component surface when machining stainless steels and titanium.
