Magnetic disk device with component materials having improved silicon content

摘要

A magnetic disk device comprising a box-shaped base; a spindle motor attached to the upper plate of the base to rotate a magnetic disk through the action of a hub; a swing arm rotatably supported at one end thereof on a pivot attached to the upper plate of the base; a magnetic head supported at the tip of the swing arm so as to be positioned over the data track of the magnetic disk; a capstan which is rotated by a step motor attached to the upper plate of the base; and a band wound on said capstan and coupled at one end of the band to the swing arm so as to turn the swing arm through the rotation of the capstan, characterized in that the swing arm is made of an aluminum alloy whose silicon content is 16+/-1% by weight; and the base is made of a die-cast aluminum alloy whose silicon content is 7.5 to 9.5% by weight.