One grade insert for virtually all steels and cast irons

Modern Machine Shop, May, 1989

One Grade Insert For Virtually All Steels And Cast Irons

Users long have been seeking the one grade insert that would cover practically all machining applications found in the shop. The "one grade cuts everything" still is not a reality, but a new development brings it much closer.

Kennametal's new KC990 multi-coated insert grade will machine virtually all steels and cast irons where the feed rates range from just above the lowest to just below the highest and speeds range from medium to high.

The KC990 is designed for the world market. Traditionally the Asian countries tended to machine at low feeds and medium speeds. Their priority was machining predictability. On the other hand, European plants accentuated medium feed rates and higher speeds. The American heritage was very high feed rates and lower speeds. The American emphasis was strictly on machining cycle time.

The trend everywhere is now toward the European approach of medium feed rates and higher speeds. To make this possible and still cover the broad range of steels and cast irons, Kennametal developed the KC990.

The multiple coatings and substrate of the new grade are micro-engineered to resist the heat and shock of high-speed metalcutting. According to Kennametal, productivity and reliability levels attainable with the inserts well exceed those attainable with conventional triphase inserts on grey, ductile, and malleable irons as well as carbon and alloy steels.

Shown in the illustration are the new grade's carbide substrate, designed with a balanced combination of deformation resistance and toughness; the TiC,N (titanium carbonitride) abrasion-resistant coating layer; the Al(2)O(3)--TiN--Al (2)O(3)...(alumina--titanium nitride) coating layers which provide the heat resistance that enables the inserts to perform well at higher cutting speeds than conventional coated inserts; and finally the TiN (titanium nitride) outer layer which contributes to lower frictional forces and reduced occurence of edge build-up.

By having only one grade for most normal machining situations, total productivity can be improved both through better machining parameters and longer tool life. The productivity sapping burdens of excessive tool inventories, multiple change-overs, and heavier extensive process engineering are also tackled by the simplicity of a longer functioning single insert grade concept.

Kennametal Inc., P.O. Box 346, Latrobe, PA 15650.

PHOTO : The KC990 multi-coated grade is suitable for rough and finish machining virtually prevalent steels and cast irons.