Steel-milling grades from Sandvik Coromant bring longer tool life to more applications

Following the introduction of its latest generation GC4330 and GC4340 steel-milling grades in 2018, Sandvik Coromant is now extending the range of application for these insert grades to additional milling concepts. For instance, the grades are now available for selection with the CoroMill 300 round-insert face and profile mill, the CoroMill 245 multi-purpose face-milling cutter, and the CoroMill QD cutter for deep and narrow grooving and parting off.

GC4330 and GC4340, which feature a specially developed substrate, Inveio coating and enhanced post-treatment technology, allow users to enjoy increased tool life and process security. Now, the extension of these grades to additional Sandvik Coromant milling concepts brings their advantages to even more machine shops looking to optimise the milling of steel workpieces.

“GC4330 and GC4340 have been designed to overcome certain issues when machining steel components,” states Karl Emil Holmström, global product application manager - grades at Sandvik Coromant. “For instance, some hard and abrasive steels can promote wear along the insert’s flank face, particularly at elevated speeds and longer time in cut. What’s more, machining in unstable conditions as a result of compromised fixtures or long overhang increases the risk of chipped inserts. A further risk is thermal fluctuation during machining which, especially in wet conditions, can lead to crack formation and sudden breakages.”

Among the many design attributes of GC4330 and GC4340 is the Inveio coating, which offers uni-directional crystal orientation in the alumina coating layer that is said to give inserts a higher level of wear resistance and tool life. Furthermore, the substrate of the grades delivers controlled grain size distribution for more reliable and predictable insert behaviour.

GC4330 is a medium-hard grade for roughing to semi-finish face milling, with the tough GC4340 grade preferred for rough shoulder milling and groove milling. Both grades are now extended to the aforementioned CoroMill 245 and CoroMill 300, as well as the CoroMill 360 heavy-duty face mill, CoroMill 419 high-feed mill, and LPMH-PM plunge-cutter inserts.

In addition, GC4330 is available for the CoroMill 365 high-security face mill, while GC4340 can be applied to the CoroMill 216 ball-nose end mill and CoroMill 415 small-diameter high-feed face mill, along with the CoroMill QD cutter.

This list adds to the existing availability of both grades for CoroMill 390 and CoroMill 490 shoulder mills, CoroMill 345 face mills, CoroMill 210 high-feed cutters, CoroMill 200 profile mills and CoroMill 331 for grooving and parting off.