Abstract: As flying height is reduced to less than 5nm,the intermolecular forces between the two solid surfaces of the slider and the disk can not be ignored.A pico slider and a femto slider,whose flying height range from 0 to 5nm,are used in this study to model the effect of the intermolecular forces on the total force.It is found that the intermolecular forces change the load capacity of the slider flying below 5nm.Due to the presence of the intermolecular attractive force,the total load decreases and even becomes negative,which means the slider can not sustain any load.When the flying height decreases further,the influence of the repulsive portion of the intermolecular force on the total force becomes dominative.Because of the dissimilar effective ranges of attractive and repulsive intermolecular forces,sliders have a critical flying height clearance in which the slider cannot sustain any load.With the slider’s form factor being different,the critical flying height clearance is not the same.