Abstract: A tangential cutting insert includes two opposing end surfaces and a peripheral side surface extending between the two opposing end surfaces. The peripheral side surface includes two opposing major side surfaces connected to two opposing minor side surfaces via corner side surfaces. A peripheral edge is formed at the intersection of each end surface with the peripheral side surface. Each end surface has two raised corners with associated raised corner cutting edges and two lowered corners with associated lowered corner cutting edges. Each of the corner side surfaces includes a concave clearance depression which serves as a relief surface for an associated lowered corner cutting edge. The concave clearance depression extends from its associated lowered corner cutting edge in the direction of, but does not intersect, a raised corner associated with opposite end surface.

Abstract: A tangential cutting insert includes two opposing end surfaces and a peripheral side surface extending between the two opposing end surfaces. The peripheral side surface includes two opposing major side surfaces connected to two opposing minor side surfaces via corner side surfaces. A peripheral edge is formed at the intersection of each end surface with the peripheral side surface. Each end surface has two raised corners with associated raised corner cutting edges and two lowered corners with associated lowered corner cutting edges. Each of the corner side surfaces includes a concave clearance depression which serves as a relief surface for an associated lowered corner cutting edge. The concave clearance depression extends from its associated lowered corner cutting edge in the direction of, but does not intersect, a raised corner associated with opposite end surface.

Abstract: A tangential milling cutting insert has two identical opposing end surfaces with two identical opposing major side surfaces of a generally parallelogrammatic shape and two identical opposing minor side surfaces extending between them. An ambidextrous tangential cutting insert has two non-identical end surfaces and two opposing major side surfaces of a generally trapezoidal nature. In either cutting insert, each end surface has a peripheral cutting edge and four corners of which two diagonally opposed corners are lowered and the other two are raised. Each end surface has four separate planar regions arranged in pairs, the planar regions do not protrude relative to the surrounding end surface and the two planar regions of a given pair of planar regions slope in opposite directions with respect to a median plane of the cutting insert.

Abstract: A drill adapter has a resilient insert retaining portion at one end, a drive stem at the second end, and an adapter seating portion between the two. The insert retaining portion includes first and second resilient clamping members which are rotationally 180° apart. The resilient clamping members are separated by a narrow slit which communicates with an internal through bore extending across a diameter of the insert retaining portion. The seating portion includes a pair of planar abutment surfaces which are supported by a lower seating surface formed on the drill adapter seating portion, when the drill is assembled. The drive stem is provided with a pair of longitudinally extending drive slots. When inserted into an end bore formed at the operative end portion of a drill shaft, the drive slots receive complementary guides formed on an inner wall of the end bore.

Abstract: A tangential milling cutting insert has two identical opposing end surfaces with two identical opposing major side surfaces of a generally parallelogrammatic shape and two identical opposing minor side surfaces extending between them. An ambidextrous tangential cutting insert has two non-identical end surfaces and two opposing major side surfaces of a generally trapezoidal nature. In either cutting insert, each end surface has a peripheral cutting edge and four corners of which two diagonally opposed corners are lowered and the other two are raised. Each end surface comprises four separate planar regions arranged in pairs, the planar regions do not protrude relative to the surrounding end surface and the two planar regions of a given pair of planar regions slope in opposite directions with respect to a median plane of the cutting insert.

Abstract: A high-speed end-milling router for ramping entry into a workpiece has plate-like hard metal cutting inserts fitted in pockets milled in chip gullet surfaces to present the insert at a desired axial rake angle and with radially inwardly and outwardly facing cutting edges. Each insert is secured in its pocket by two countersink headed machine screws whose holding power against centrifugal dislodgement of the insert is reinforced by an interfitting boss integral with and upstanding from the seating surface of the pocket extending into a blind recess molded in the undersurface of the insert.