At EMO Hannover last month, the French precision toolmaker Safety presented a new cutting-grade material —8625 — which replaces the current grade 8525. This high-performance turning grade has an MT-CVD (Medium Temperature Chemical Vapor Deposition) coating, with high coating adhesion. A newly developed, fine-grained high-cobalt substrate withstands very high temperatures and resists plastic deformation, preventing early formation of built-up edges. Due to the coating’s alternating multiple layers of titanium carbonitride (TiCN), for abrasive wear resistance, and aluminum oxide (Al2O3) for high temperature resistance, and a gold-colored surface layer of titanium nitride (TiN) on the rake face, edge chipping and damage are reduced.

Safety claims that the tool life of these coated inserts is considerably increased.

"Our new 8625 cutting material is a highly efficient and reliable solution for turning stainless steels," stated Holger Rabe, managing director of Safety Germany, "with it we can cover 80 percent of potential applications."

Depending on the cutting geometry, 8625 is well suited to a variety of cutting tasks from light pre-finishing to roughing, even with a continuous cut. As demonstrated by application tests at Safety's CEROC laboratory France, the new grade is the material of choice for high cutting speeds (vc up to 240 m/min).

Turning inserts in 8625 quality are available now from stock. The application area M25 is optimized for stainless steel (austenitic, ferritic, PH & Duplex), however low-carbon steels and alloys with a nickel or cobalt base also can be machined easily. Inserts are available in many commonly required sizes in both positive (PM4, PM5) and negative geometries (F5, M4, M5, M7, 5G) as well as KNUX shape inserts.