Tool bit with work-hardening section

A machining device comprising:

• a tool;
• a linear motor comprising a core and stator that each surround a longitudinal feed axis, the linear motor operable to provide linear movement of the tool relative to the stator along the longitudinal feed axis, and superimpose oscillation of the tool onto the feed axis during the linear movement;
• a rotary motor operable to rotate the tool about the longitudinal feed axis during the linear movement;
• and
• a controller operable to cause the linear motor to provide the linear movement and superimpose the oscillation by oscillating a direct current (DC) control signal provided to the linear motor;
• the tool comprising
• a shaft defining a bit axis and having a first end and a second end, and
• a work-hardening section adjacent the second end, the work-hardening section having a profile that either is cylindrical or is a portion of a sphere, the work-hardening section defining a smooth working surface.

A method comprising:

• oscillating a direct current (DC) control signal provided to a linear motor, and thereby causing the linear motor to provide linear movement of a tool along a feed axis relative to a workpiece and to oscillate the tool during the feed movement, such that the oscillation is superimposed onto the linear movement;
• and
• rotating the tool about the feed axis during the linear movement, as part of a machining operation,
• the tool comprising
• a shaft defining a bit axis and having a first end and a second end, and
• a work-hardening section adjacent the second end, the work-hardening section having a profile that either is cylindrical or is a portion of a sphere, the work-hardening section defining a smooth working surface.