Base plate, motor, disk drive device, and method for manufacturing base plate

A method for manufacturing a base plate defining a portion of a housing of a disk drive device, the method comprising, in this order:

• a casting step of integrally casting, by using a mold, a bottom wall extending perpendicularly to a rotation axis of a disk, the rotation axis extending in a vertical direction and a swing axis of a head configured to read or write information from or to the disk, a pivot post protruding upward from an upper surface of the bottom wall along the swing axis, and a pedestal having an annular shape and protruding radially outward from an outer circumferential surface of a root portion of the pivot post;
• and
• a precision cutting step of cutting a portion of the bottom wall;
• wherein
• in the casting step, the bottom wall is integrally formed with a thick portion having a thickness of about 2.0 mm or more in the vertical direction in a peripheral region on a radially outer side of the pedestal;
• and
• in the precision cutting step, the thick portion is cut, and a cut surface formed by cutting is formed on at least one of an upper surface or a lower surface of the bottom wall.