Countersinking tool, tool arrangement and method

A countersinking tool, comprising a tool shank and a tool head that features multiple deburring or countersinking edges and an insertion pin, wherein:

• the insertion pin features at least one reaming edge, which is arranged on a radially outer side and extends over less than 33% of the overall length of the insertion pin,
• an external surface of the insertion pin comprises a first surface region and a second surface region,
• the first surface region defines a cylindrical shape, the cylindrical shape has a cylindrical axis that is coaxial with an axis of the countersinking tool, the entirety of the first surface is between a first imaginary plane and a second imaginary plane, the first imaginary plane is perpendicular to the axis of the countersinking tool, the second imaginary plane is perpendicular to the axis of the countersinking tool and is spaced from the first imaginary plane,
• an entirety of the second surface region is between the second imaginary plane and a third imaginary plane, the second surface region has diameters, in directions perpendicular to the axis of the countersinking tool, that are smaller at greater distances from the second imaginary plane, the second surface region is curved along a fourth imaginary plane in which an entirety of the axis of the countersinking tool extends,
• the at least one reaming edge extends from a first location on the second surface region to a first location of the first surface region, and
• the reaming edge can be inserted into an unfinished bore with a diameter, which is smaller than a nominal diameter of the bore, in a cutting fashion, wherein the reaming edge likewise acts as a drill bit and is arranged on the insertion pin at a radius that essentially corresponds to the radius of a nominal diameter of the bore, and wherein the insertion pin has the nominal diameter of the bore and can be guided in the bore without play.