Abstract: A tool holder for a lathe having a spindle permits improved arrangement of tools on a turret to maximize the allowable workpiece outer diameter for a given tool. A Z-axis feed mechanism moves the spindle and the turret relative to each other in a Z-axis direction along a center axis of the spindle, while an X-axis feed mechanism moves the spindle and the turret relative to each other in an X-axis direction orthogonal to the Z-axis direction. A plurality of tool holders is attached to the turret, each having a tool holding part. At least one of the tool holders holds the tool at a holding position such that, when indexed to a machining position by rotation of the turret, a cutting-edge reference point of the tool is offset with respect to an X-Z plane including a center axis of the turret.

Abstract: A lathe includes a spindle, a turret, a Z-axis feed mechanism moving the spindle and the turret relative to each other in a Z-axis direction along a center axis of the spindle, an X-axis feed mechanism moving the spindle and the turret relative to each other in an X-axis direction orthogonal to the Z-axis direction, and a plurality of tool holders each having a tool holding part holding a tool, and attached to the turret. The tool holding part of at least one of the tool holders holds the tool at a holding position thereon set at a position such that, when the held tool is indexed to a machining position by rotation of the turret, a cutting-edge reference point of the held tool is offset to one side with respect to an X-Z plane including a center axis of the turret.