A method used to predict a strength of an ultrasonic weld-joint of a wire-cable comprising the steps of providing a wire-cable, determining a combined-weight, removing a contaminant, determining a weight, determining a percentage by weight of the contaminant, and determining whether the percentage by weight of contaminant is less than a threshold. Determining the percentage by weight of the contaminant removed from the wire-cable is based on a formula [(Mb−Ma)/Mb]*100, where Mb is the combined-weight of the wire-cable and the contaminant and Ma is the weight of the wire-cable. The threshold of the percentage by weight of the contaminant correlates to the strength of the ultrasonic weld-joint.