Machine tool system and workpiece transport method

A machine tool system comprising:

• a lathe;
• a machining center disposed side by side with the lathe;
• and
• a loader that carries a workpiece;
• wherein
• the lathe includes:
• a lathe-side workpiece holder that holds the workpiece such that the workpiece faces a front side;
• a main spindle that rotates around an axis;
• and
• a tool that machines the workpiece;
• the machining center includes:
• a rotary tool that rotates around an axis in a horizontal direction;
• and
• a machining center-side workpiece holder that holds the workpiece and is able to turn between a first position in which the machining center-side workpiece holder holds the workpiece such that the workpiece faces the front side and a second position in which the machining center-side workpiece holder holds the workpiece such that the workpiece faces the rotary tool;
• and
• the loader includes:
• a guide extending above the lathe-side workpiece holder and the machining center-side workpiece holder along the horizontal direction;
• and
• a loader head that holds the workpiece and carries the workpiece, by moving along the guide, between the lathe-side workpiece holder and the machining center-side workpiece holder in the first position.