Provided is a roller assembly for a storage device. The roller assembly includes a shaft member, a rolling member, a cover member, and ball members. In particular, the ball members are configured to perform a rolling operation while being maintained in the state of being seated at specific locations by a seating groove formed in the shaft member and guide grooves formed in the rolling member and the cover member, and the rolling member and the cover member are configured to be coupled to each other by a fitting method and are then completely coupled to each other through laser bonding. The roller assembly is additionally characterized in that the damage of the ball members is prevented from occurring during the above laser bonding.