"Being 100% assured of zero pull-out for Weldon shanks when producing high value-added parts, such as aerospace frame or engine components, is paramount in the highly competitive manufacturing arena,” says Mats Backman, global product manager at Sandvik Coromant. “Production engineers and managers are under constant pressure to minimise scrap and maximise bottom-line profitability. These thoughts were the driver for developing the new collet.”

The mechanical locking interface acts between the collet and chuck, and between the collet and shank. Having confidence in zero pull-out when both collet and chuck are locked enables increased productivity in heavy-duty applications. Further benefits include easy assembly into CoroChuck 930 chucks, both slender and HD versions, while high run-out accuracy is assured with the cylindrical clamping of Weldon shanks. In addition, coolant supply through the collet provides secure and reliable coolant delivery to the tool.

Pull-out during machining is known to affect the gauge length of the tool mid-cut, leading to the generation of features with incorrect dimensions or crash marks.

According to Sandvik Coromant, its latest collet solution will benefit any machine shop seeking trouble-free machining in heavy-duty operations. Zero pull-out or tool movement protects against the potentially sizable cost of reworking or scrapping an expensive component.

To provide an example of the potential gains on offer, a customer case trial saw CoroChuck 930 (featuring the new collet) used for a milling operation on a CNC turn-mill machine. The objective was to produce a twin-screw from 42CrMo4 alloy steel. At cutting data of 3,220 rpm spindle speed, 1,500 mm/min feed speed, 10 mm axial depth of cut (nominal), and 20 mm radial depth of cut, the mechanical locking interface generated a stable process with no pull-out. In addition, productivity increased due to longer tool life.

Collets are available to suit an assortment of common Weldon shank sizes. Accessories include assembly tools and anchor screws.