Magnetic disk device and suspension having multiple arm portions of varying lengths

A magnetic disk device comprising a disk that records information,

• a slider mounting thereon a magnetic head that records or reproduces information from the disk, and
• an actuator mounting thereon the slider on a tip end side thereof turnably so as to move radially of the disk, and
• wherein the actuator comprises a suspension mounting the slider on a tip end side thereof to give a predetermined load to the slider, and an arm holding the suspension and supported to be able to turn,
• wherein the arm comprises two arm portions juxtaposed in a direction perpendicular to a surface of the disk, and a spacing between the two arm portions on supported sides thereof in the direction perpendicular to the surface of the disk is made larger than another spacing between the two arm portions on a side of the slider in the direction perpendicular to the surface of the disk;
• and
• wherein the arm portion on an opposite side to a surface of the disk is larger in length than the arm portion on a side toward the surface of the disk.