A cutting tool and cutter body assembly, including a disk-shaped cutter body and a plurality of support pads removably retained therein, the cutter body having an axis of rotation, two opposing end surfaces and a body peripheral surface extending therebetween. Each support pad intersects one of two annular-shaped planes equidistantly offset from opposite sides of a median plane perpendicular to the axis of rotation, and the cutter body intersects neither of the two annular-shaped planes. Each support pad is configured to make operative contact with a machined surface of a workpiece perpendicular to the axis of rotation. Each support pad has opposing upper and lower surfaces and a pad peripheral surface extending therebetween, the pad peripheral surface having an upper portion intersecting the upper surface, and the upper portion exhibiting N-fold rotational symmetry about a pad axis non-perpendicular to the lower surface.

A drill head for deep-hole drilling includes cutting blade tips brazed to cutting chip discharge ports opened on a head distal end surface, guide pads mounted on a plurality of positions of the circumferential surface at the head distal end side, and a hollow inside portion made into a cutting chip discharge passage communicating with the cutting chip discharge ports. A guide pad portion having an arc surface that slide-contacts with the inner circumference of a cutting hole is formed on the outer end surface of the circumferential portion cutting blade tip.

A deep hole drilling system and methods provide stability and cutting performance to produce deep holes having desired straightness. The system may include a replaceable cutting head provided with a center cutting member and first and second side cutting inserts. The tool provides a major diameter with the OD cutting margins on the replaceable side inserts, as well as possibly cutting margins on the center cutting member. Adjustment mechanisms are provided to adjust the center cutting member and/side cutting inserts.

A rotating cutting tool configured to rotate around an axis of rotation in a rotary direction, and a support pad for such a tool is disclosed. The support pad defines a central longitudinal axis and has a first longitudinal edge side, an opposite second longitudinal edge side, a first transversal edge side and an opposite second transversal edge side. The support pad includes a first support surface, which is convexly curved as viewed in a plane perpendicular to the central longitudinal axis and a first recess, which extends into the first support surface in a direction from the first longitudinal edge side towards the second longitudinal edge side. The first recess extends to a final position on the first support surface.

Provided are a guide pad having sufficient strength and a gun drill having the guide pad. A guide pad includes: a first surface; a second surface that is a flat surface located at a position opposed to the first surface; and a third surface that connects the first surface and the second surface to each other. When viewed along a rotational center axis, the first surface is a circular-arc-shaped surface, and when a point at which a virtual line passing through a circular-arc center of the first surface and perpendicular to the second surface and the second surface cross each other is assumed as a first point and a point at which a central axis of the through hole and the second surface cross each other is assumed as a second point, the first point is located at a position closer to the third surface than the second point.

Provided is a body capable of suppressing the bending of the body during machining. A body includes: a first attachment part serving as a portion that is provided on a leading end side and has a cutting edge mounted thereon; and a second attachment part serving as a portion that is provided at a position different from a position of the first attachment part along a circumferential direction and has a guide pad attached thereto on the leading end side. One discharging groove that extends from the leading end side to a base end side and is used to guide and discharge a fluid to the base end side is formed on an outer peripheral surface of the body, and at least a part of the discharging groove is bent.