Patent classifications
B23B2233/04
Material to be worked in face driving and method for working the same
Provided is a material to be worked in face driving, which can facilitate making a face driver hold the material and can prevent a slide in the rotating direction between the face driver and the material, and a method for working the material. The material is to be worked with one end surface thereof held by the face driver having a center pin and a plurality of driving claws arranged around the center pin. A center hole into which the center pin is fit is formed on the one end surface. A recess or a protrusion existing in every phase in a circumferential direction around the center hole is formed on the one end surface. The recess or the protrusion is arranged within an area of the one end surface in a radial direction of the one end surface, into which the driving claws are driven.