Definitions to European standard EN 818-7 For the purposes of this Part of EN 818,the following definitions apply: 1. nominal size: Nominal diameter of the round section steel wire or bar from which the chain is made. 2. material diameter: Diameter of the material in the chain link as measured. 3. weld diameter: Diameter at the weld as measured. 4. length dimensionally affected by welding: Length on either side of the center of the link, affected by welding. 5. pitch: Internal length of a link as measured. 6. manufacturing proof force(MPF) of chain: Force to which during manufacture the whole of the chain is subjected. 7. breaking force( BF): Maximum force which the chain withstands during the course of a static tensile test to destruction. 8. working load limit (WLL) of chain: Maximum mass which the chain hanging vertically is authorized to sustain in general lifting service. 9. total ultimate elongation (A): Total extension at the point of fracture of the chain expressed as a percentage of the internal length of the test sample. 10. processing: Any treatment of the chain subsequent to welding, for example, heat treatment, polishing or dimension calibration. 11. lot: Specified quantity from which test sample(s) is/are selected. 12. competent person: A designated person, suitably trained qualified by knowledge and practical experience, and with the necessary instructions to enable the required examination to be carried out.