A tool shank has a head receiving pocket at a forward end, and a plurality of chip flutes extending rearwardly therefrom along a longitudinal axis. The head receiving pocket has a support surface transverse to the longitudinal axis. A central recess is formed in the support surface and extends rearwardly therefrom. The central recess has a plurality of resiliently displaceable abutment portions circumferentially alternating with and spaced apart by a plurality of intermediate portions. Each abutment portion has a radially inward facing abutment surface, and each intermediate portion has an intermediate surface intersecting two circumferentially adjacent abutment surfaces. A rotary cutting tool includes the shank and a cutting head releasably mounted thereto. The cutting head has a mounting portion provided with a base surface and an engagement member protruding therefrom. In an assembled position, the engagement member is resiliently retained in the central recess against the plurality of abutment surfaces.

In the drill, each of the thinning edges extends beyond an intersection point with the chisel; an axial rake angle is in a range of +5 to +15; and a ratio of a length of each of the thinning edges to a length of each of the cutting edges in a direction, in which the main cutting edge extends as viewed from the front side of the axial direction, is in a range of 20% to 50%. Intersecting ridges between: second thinning wall surfaces facing an opposite side of the drill rotation direction; and the tip flank faces, are disposed that: they are spaced apart in a direction orthogonal to the intersecting ridges; they are positioned on one diameter line passing the axis; or they mutually pass over in a passing over amount of 0.03D or less with respect to a diameter of the cutting edges.

A drill of the present invention includes: a drill main body; a plurality of convex-arc cutting edges which are formed on a tip side of the drill main body from an outer periphery of the drill main body to a chisel edge provided near to a rotational axis; second faces which are each formed in an approximately band shape and are each formed along each of the convex-arc cutting edges on a back side of the convex-arc cutting edge in the rotational direction; third faces which are each formed to be continuous with a back side of each of the second faces in the rotational direction; and fourth faces which are each formed to be continuous with a back side of each of the third faces in the rotational direction.

A drill bit includes a shank, a transition portion, and a body portion defining a plurality of axially stacked, progressively sized steps. The steps include a first step and a terminal step coupled to the transition portion. The first step defines two tip flutes each disposed at a tip flute angle. The body portion defines a body flute extending from the first step to the transition portion. The drill bit also includes an indicator band formed on a portion of the body flute and a portion of an outer surface of one of the plurality of steps.

A drill includes a front and rear end, a shaft extending axially rearwardly from the front end, at least one cutting insert releasably mounted at the front end, a first and second chip flute in an envelope surface of the shaft, a coolant chamber inside a shank, and a first and second coolant channel extending from the front end of the coolant chamber and terminating at the drill front end. The first coolant channel is associated with the first chip flute and the second coolant channel is associated with the second chip flute. The coolant chamber includes a flow control element movable in response to a flow restriction between a neutral position, in which coolant flow is distributed substantially equally to the first and second coolant channels, and an active position, in which the flow control element directs the coolant flow at least mainly to one of the coolant channels.

A rotary cutting tool includes a tool body including a chip flute portion having a plurality of helical chip flutes separated by lobes. In one aspect, a tunable vibration absorber assembly is disposed within a cavity formed in the chip flute portion. In another aspect, the tunable vibration absorber assembly is disposed within a cavity of a replaceable cutting head. In each aspect, the tunable vibration absorber assembly includes at least two tunable absorber masses, a resilient material between the one or more absorber masses and the cavity, and one or more connecting members for preventing relative angular displacement of the one or more tunable absorber masses. The at least two tunable absorber masses are suspended only by the resilient material, thereby enabling the tunable vibration absorber assembly to be tuned to a desired frequency for suppressing torsional vibration of the rotary cutting tool during a cutting operation.

To provide a drill having high rigidity and excellent chip discharging property while reducing the occurrence of damage on a front end side. A drill according to one aspect of the present disclosure includes a body extending along a rotation axis. The body has a cutting edge, a thinning flute, a discharge flute, a front end surface, a first honing surface, and a second honing surface connected to the first honing surface. The first honing surface includes a first portion that is connected to the second honing surface and that has a width that increases toward the second honing surface in a front end view. The second honing surface includes a second portion that is connected to the first honing surface and that has a width that increases toward the first honing surface in a front end view.

A drill bit including a body extending from a shank to a point angle, wherein the body includes a plurality of steps each associated with a different cutting diameter; a first groove disposed between a first pair of adjacent steps of the plurality of steps and radially inset from an outer diameter of each of the first pair of adjacent steps; and a first visual indicator disposed in the first groove.

A drill bit includes a shank and a body portion defining a plurality of axially stacked, progressively sized steps. The steps include a first step and a terminal step. The first step defines two tip flutes each disposed at a tip flute angle. The body portion defines a body flute extending through the steps. The drill bit also includes an indicator band formed on a portion of the body flute and a portion of an outer surface of one of the plurality of steps.

A drill bit includes a shank extending along a bit axis and a body portion coupled to the shank. The body portion having a distal end and defining a plurality of axially stacked, progressively sized steps. The body portion defining a body flute having a flute surface. The drill bit includes a first indicium formed on the flute surface adjacent a first step of the plurality of steps, the first indicium including a number and an indicator band around the number and a second indicium formed on the flute surface adjacent a second step of the plurality of steps and spaced from the first indicium, the second indicium including a number and an indicator band around the number, wherein the first indicium is spaced from the second indicium by at least one step of the plurality of steps.