Patent ID: 8233239

Claim:
A disk drive comprising: a disk drive base; a rotary spindle attached to the disk drive base; a disk attached to the rotary spindle; a head stack assembly attached to the disk drive base, the head stack assembly comprising: a first actuator arm, having a first actuator arm tip that includes a first swaging hole, the first swaging hole being centered about a swaging axis; a first suspension assembly having a first swage boss that protrudes into the first swaging hole, the first swage boss being annular about the swaging axis, a first read head being attached to the first suspension assembly; and a second suspension assembly having a second swage boss that protrudes into the first swaging hole, the second swage boss being annular about the swaging axis, the second swage boss not contacting the first swage boss; wherein the first swage boss includes a first inner lip, the first inner lip extending radially closer to the swaging axis than any other part of the first swage boss, the first inner lip defining a first inner lip thickness measured parallel to the swaging axis; wherein the second swage boss includes a second inner lip, the second inner lip extending radially closer to the swaging axis than any other part of the second swage boss, the second inner lip defining a second inner lip thickness measured parallel to the swaging axis; and wherein the first inner lip thickness increases more greatly with increasing radial distance from the swaging axis than does the second inner lip thickness.