Sandvik Coromant has introduced GC1240, an indexable milling grade developed for stainless steel machining applications where thermal cracking, abrasive wear, flaking, and chipping can restrict tool life.
The new grade uses a nano-multilayer physical vapour deposition coating produced with Sandvik Coromant’s Zertivo coating process technology. The coating combines TiAlN and TiSiN to provide edge line toughness and wear resistance, targeting a balance that is often difficult to achieve in stainless steel milling.
GC1240 has been developed for light roughing to finishing operations using strong, positive, and sharp geometries. It is suitable for wet and dry machining, with Sandvik Coromant describing it as a first-choice grade for stainless steel, particularly austenitic materials, in stable machining conditions. The grade can also be used in heat-resistant super alloys and titanium at recommended cutting speeds.
Stainless steel remains a demanding material group for milling because of heat generation, work hardening, built-up edge formation, and thermal cycling at the cutting edge. Inconsistent edge stability can lead to poor surface finish, premature insert failure, or narrow process windows, especially where production teams are reducing coolant use or increasing cutting speeds.
Wayne Mayson, Global Product Application Manager for Grades at Sandvik Coromant, said: “GC1240 has tremendous capability to machine stainless steel at higher cutting speeds in dry conditions — in some cases up to 20% higher than wet machining. This enables reduced energy consumption, more parts produced in less time, and a reduction in coolant usage, contributing to reduced CO₂ emissions and improved sustainability.”
Dry cutting places greater thermal stress on the insert, making edge integrity and coating stability central to process reliability. A grade capable of maintaining performance under higher thermal loads gives production engineers more room to balance cycle time, tool life, energy consumption, coolant use, and component quality.
GC1240’s coating architecture improves resistance to thermal cracks and heat-related wear while maintaining a stable edge line. Sandvik Coromant says the result is more predictable tool life across operations ranging from light roughing to finishing.
The grade is being made available across 13 CoroMill families, covering 77 individual articles. The range includes established milling platforms used in shoulder milling, face milling, ramping, high-feed machining, and other stainless steel applications.
Mayson added: “GC1240 is the first-choice indexable milling grade for stainless steel, particularly austenitic materials, in stable conditions. GC1240 unlocks higher productivity, lower cost per part, and new sustainability opportunities through impressive and tangible results. Try it with confidence, you will not be disappointed.”
Further product details are available through Sandvik Coromant’s stainless steel milling grades resource.
