The amount of lifting weight is not the only factor to choose the right wire rope sling. in many cases one of the deciding factors to pick the right type, size and right number of legs for a wire rope sling is the volume of the weight. different kinds of lifting rigging are used on 4 legged wire rope slings including hooks and shackles.
Different legs of the wire rope sling have different effect in picking the weight and do not undergo exact equal weight and pressure. the more the angle with the vertical line the lower effect the sling leg will have.