Magnetic disc apparatus with slider having specified location of action point of equivalent load

A magnetic disc apparatus comprising a magnetic disc having a surface and rotatably mounted on a spindle, a slider incorporating lifting rails or lifting pads opposed to the surface of the magnetic disc, for inducing a positive pressure, and a magnetic head provided to a lifting rail or a lifting pad on the outflow end side, for recording and reproducing data to and from said magnetic disc, a suspension supporting the slider, for applying a predetermined urging force to the slider, and a carriage attached to said suspension, for positioning said slider on the magnetic disc,

• said slider having an inverted stepped wall formed in a shape such that it is caved in a direction from the inflow end to the outflow end of the slider, and a bleed surface formed at the outflow end side of the inverted stepped wall and caved from the lifting rails or the lifting pads, for producing a negative pressure force which is the resultant force of negative pressure applied upon an opposed surface of the slider with respect to the magnetic disc,
• an action point of an equivalent load which is a resultant force, perpendicular to the surface of the magnetic disc, between a force and a pitching moment exerted to the slider by the suspension, on the slider, which is an equivalent load point is located offset from the inverted stepped wall of said slider toward the inflow end of said slider.