The concept of a Weight Bar
is relatively basic. Free weights, also referred to as plates, sleeve onto the ends of a steel bar that has integral stops near each end. According to Cross Fit Journal, "A barbell is made out of a material known as Drawn Over Mandrel (DOM) tubing, a type of machine tubing that is made out of flat stock." The integral stops serve as backing at the inner side of the free weights, and collars fit against the outer side of the weights to hold them into place on the bar. With most designs, the collars are spring clips or polished steel nuts. Weightlifters grip the bar with both hands evenly spaced and then perform lifting exercises. The amount of weight a bar is intended to hold will often dictate the level of manufacturing that is necessary.