US Patent 7097393 Tangential cutting insert and milling cutter

A tangential cutting insert having first and second opposing end surfaces and a peripheral side surface extending therebetween. First and second edges are formed at the intersection of the first and second end surfaces with the peripheral side surface. A groove in the peripheral side surface extends between and intersects the first and second end surfaces at first and second minor edges. In first and second opposing side views of the cutting insert, at least the first edge is generally concave.