What thickness must edge discs weighing 5kg or less not exceed?

The specific requirement for edge discs weighing 5kg or less is that their thickness must not exceed 3 cm. This standard is established to ensure consistency in equipment used during competitions, as thicker discs could potentially influence the mechanics of lifting or interfere with safety measures, such as proper alignment of the barbell during a lift. Maintaining a maximum thickness ensures that all lifters are competing on a level playing field, without the effects that could arise from variations in equipment dimensions. Thus, the threshold of 3 cm provides a suitable balance between durability and competitive fairness in powerlifting events.