Patent ID: 7603999

Claim:
A metal bonded drilling and boring tool comprising: a rod-shaped body having a substantially semispherical front end portion at a center thereof and a first diameter said rod-shaped body being solid in cross-section; an enlarged mounting portion having a second diameter larger than said first diameter, said enlarged mounting portion having a mounting hole with an internal screw thread; a connecting portion connecting said rod-shaped body and said enlarged mounting portion; and numerous abrasive grains brazed by a brazing member to an outer circumferential surface of said rod-shaped body at said front end portion and extending a given length from said front end portion to include a part of said connecting portion, wherein said rod-shaped body has an arcuate depression formed on said front end portion at the center and in the vicinity thereof, wherein said arcuate depression defines an arc extending into the rod-shaped body in an axial direction with endpoints along a circumferential interface between said depression and said front end portion surrounding said depression.