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Effective alternative to tapping

Sept. 21, 2007
Gentz Industries realized a 66 percent gain in productivity by switching to Seco Threadmaster thread mills for machining a turbine combuster case component. Seco Tools Inc. (www.secotools.com) said its new Threadmaster line of ...

Gentz Industries realized a 66 percent gain in productivity by switching to Seco Threadmaster thread mills for machining a turbine combuster case component.

Seco Tools Inc. (www.secotools.com) said its new Threadmaster line of small, solid-carbide TiCNcoated threadmills produces threads with higher quality than tapping, reduces cost and improves productivity. The company said the tool’s rigid, large-diameter shank allows for high feed rates, short cycle times, low vibration and long tool life. The threadform is ground with a high spiral relief that reduces cutting forces — a particular advantage when threading hardened materials. Available in all common tap sizes, Threadmaster’s tough, wear-resistant TiCN coating makes it well-suited for thread milling of steel, stainless steel, cast iron and high-temperature materials. Coolant holes on thread mills with shank diameters of 8 mm, and larger, aid chip evacuation, tool life and surface finish.

The Threadmaster threadmills were put to the test at Gentz Industries, a manufacturer of complex turbine engine components for commercial and military applications.

Mark McWilliams, purchasing manager for Gentz, said he was initially skeptical when Seco application engineer Belinda Smith suggested switching to a 0.156 in. Seco Threadmaster threadmill to produce 52 #10-32 threaded holes on a combuster case component made of Inconel 718 heat-treated to 42 Rc. Gentz previously tested five competitive 0.156-in. thread mills on the application, but they all resulted in tool breakage. Although Gentz’s current thread milling operation was not highly efficient, it was stable.

Curt Hassan, Seco regional manager, suggested when trying the Threadmaster tools that Gentz more than double the current feedrate from 78 ipm to 194 ipm, and speed up the machining center from 1,500 rpm to its 5,000 rpm capacity.

The new Seco Threadmaster 0.156-in. thread mill completed the thread milling operation in 53 minutes with only two passes, saving an hour in machining time and one complete pass. Additionally, hand-tapping time was reduced from 90 minutes average per component to 30 minutes.

“Just eliminating the hand-tap time was worth the change in this process, and, you can’t scoff at almost $62,000 per year in savings,” sid Roger Bartolomei, chief operating officer for Gentz.