Halesowen-based Sandvik Coromant, a cutting tool and tooling system specialist, has introduced a new grade in its new generation steel turning series. Grade GC4405 is first choice for high metal removal rates in stable conditions, especially in harder steels. The possibility to machine dry in softer steels opens up for more sustainable machining. The company has also recently introduced steel turning grades GC4425 and GC4415. These new generation grades have been refined in every aspect, and can deliver an average 25% increase in tool life compared to previous grades — a significant increase.

Torbjörn Ågren, product application specialist at Sandvik Coromant, said: “With the introduction of GC4405, we are complementing the steel turning grade chain within the high-feed roughing area. We strive to make it as easy as possible to choose and apply the correct grade to match a specific application.”

Grade GC4425 delivers wear resistance, heat resistance and toughness in a wide application range, while grade GC4415 complements GC4425 with enhanced performance when more heat resistance is needed. Grade GC4405 should be applied as a high-feed productivity optimiser with high metal removal rates in stable conditions where plastic deformation properties are demanding.

Higher productivity
Among the features coming with the new grade is a new carbide substrate with optimised microstructure, which will reduce plastic deformation in high-feed applications. The substantial increase in plastic deformation resistance has enabled a drastic expansion in the application range towards harder steels and higher productivity compared to existing grade GC4305.

New grade GC4405 features second-generation Inveio technology coating, with this coating version designed specifically to combat crater wear common to P05 applications. What makes second-generation Inveio different from the earlier generation is the alumina coating, where the crystals are lined up in an even more vertical orientation towards the top surface to improve wear resistance, bringing a more consistent quality and performance.

The new grade provides a considerable increase in productivity and tool life, particularly when machining steels above 300 HB. The grade is also suitable for machining softer steels — in this case without the need of coolant, which is a noteworthy opportunity from a sustainability point of view.

Comprehensive tests conducted between existing GC4305 and next-generation steel turning grade GC4405 indicate an increase in tool life ranging from 30% up to 130%, mainly a result of significantly improved plastic deformation and crater wear resistance.

Grade GC4405 is recommended for continuous roughing to semi-finishing in stable conditions and long time in cut. It is suitable for high-feed machining with medium, roughing or wiper geometries in harder steels above 300 HB or for high-feed and/or high-speed machining in softer steels below 300 HB.

The grade should be applied in ISO application area P05 (P01–P10). It is optimised for P2.5 low-alloyed hardened steel, but also recommended for high-productivity applications in low-alloyed P2.1 and unalloyed P1.2 steel.