Drilling tools and inserts with coolant relief and method

A drilling system comprising,

• a holder having a rotational axis and drill insert mounting end, a shank and coolant delivery outlets,
• a drill insert formed as a body with bottom, top, first and second side locating surfaces together locating the drill insert body with respect to the holder and land surfaces at the outside diameter, the top including a plurality of cutting edges,
• wherein the land surfaces each form an interface with the side of a drilled hole over at least a portion thereof, the interfaces having leading and trailing edges, and wherein at least one coolant supply channel extends between the leading and trailing sides of the interfaces at an acute orientation angle with respect to the thickness of the drill insert and plane of the interface from the cutting edges toward the bottom of the drill insert for coolant to enter from the bottom of the drilled hole and be dispersed in the area adjacent the trailing side of the interfaces.

A method of dispersing coolant in a drilling operation using a drilling tool comprising

• a holder having first and second ends and a rotational axis, with a drill insert configured to be fixed in association with the first end and the second end of the holder, and wherein the drill insert includes bottom, top, first and second side locating surfaces together locating the drill insert body with respect to the holder, first and second cutting edges on the top extending from the rotational axis, and first and second land surfaces at the outside diameter of the drill insert with at least a portion of the land surfaces forming an interface with the wall of a drilled hole, wherein at least one coolant supply channel extends through the interfaces from the leading to the trailing edges of the interfaces at a transverse angle toward the second mounting end from the leading edge, and drilling a hole in a workpiece while directing an amount of coolant under pressure toward the bottom of a drilled hole, wherein the at least one coolant supply channel provides coolant to flow through the interfaces and adjacent the trailing edge of the interfaces at the outside diameter of the drill insert.