Barbell weights are still considered to be used in resistance exercises. They clip onto the ends of a barbell — hence, why different resistance levels are achievable. For one particular exercise, subjects could differ in weight, eg, whether they do squats or arm flexion exercises like biceps curls. This breakdown of these plates can be quick and precise because weights are written in kg But wait! But wait (so they say) — each individual plate, too comes with a set of hole tolerances. It barbell plates are oftener than not to get made out of materials like cast iron, rubber or urethane specifically for quality and tight anti corrosion too. Barbell plates are some of the most versatile pieces of equipment. This simple piece of exercise equipment is beneficial for the beginner and professional athlete a like whether it be for using flur the squat, bench or dead laps.