This invention relates to an actuator armset for a computer disk drive. In accordance with one aspect of the present invention, the armset is comprised of a magnesium alloy containing beryllium. The armset has a bore for rotating about a spindle of the disk drive to position a transducer radially across a disk of the disk drive. The present invention is further directed to an actuator armset of a disk drive system for movably positioning and supporting a transducer over a disk of the disk drive. The armset has a bore for pivoting about a spindle and comprises a magnesium alloy containing beryllium. A bearing assembly is interposed between the armset and the spindle, a flexible suspension being mounted at one end of the armset. Mounted to an opposing end of the suspension is a transducer. A voice coil is, in turn, mounted to a set of armset brackets such that the voice coil and the brackets are opposite the suspension and transducer.