Weight plate

[20] Plates can be weighed, and the equipment marked (using a paint pen or other permanent marker) with the true weight.

These are used for Olympic weightlifting, a category of movements that involve lifting a barbell high overhead, then letting it fall.

[25] Their design permits a loaded barbell to be dropped (and to bounce) after a lift, with negligible damage to the floor, plates, and bar.

This helps to distribute the force of the dropped barbell across all the plates more evenly, reducing damage to the equipment.

Their primary purpose is to allow novice lifters to practice Olympic lifts at lighter weights that can put too much lateral stress on single pairs of rubber plates, damaging them.

[33] Standard (25 mm hole) "vinyl" plates are often sold paired with dumbbells or barbells as a low-cost option for casual strength training.

The cement tends to break down over time and leak out of holes in the sheath, and the weights are less dense than iron so that fewer fit on a given bar.