Plate-like apparatus, rotating body built-in device, and disk device

A data storage and retrieval system, comprising:

• a base having a longitudinal dimension, a width dimension, a thickness dimension, and side walls extending in a width direction, the base being formed from a first material;
• a pair of guide grooves located on opposite sides of an exterior of to base and extending in the width direction, each of the guide grooves being defined by one of the side walls and first and second overhangs that extend in a longitudinal direction;
• and
• at least a portion of each of the first overhangs is formed from a second material that is softer than the first material of the base such tat the second material is a shock absorber, and the second overhang are formed entirely from the first material of the base.

A data storage and retrieval system, comprising:

• a base having a generally rectangular shape that defines four corners, a longitudinal dimension, a width dimension, a thickness dimension, and side walls extending in a width direction;
• means for storing data located in the base;
• a pair of guide grooves located on opposite sides of an exterior of the base and extending in the width direction, each of the guide grooves being defined by one of the side walls and first and second overhangs that extend away from the base in a longitudinal direction;
• and
• a step formed in one of the first overhangs such that a thickness dimension between said one of the first overhangs and an adjacent one of the second overhangs is greater than a thickness dimension between the other one of the first overhangs and the other one of the second overhangs.