In this paper, a concurrent functional tolerance design process is presented. The field of tolerance research is briefly reviewed to determine the new developments needed for a complete set of concurrent tolerance design tools. Motivated by this approach, the novel notion of metamorphosis for tolerance design is introduced and developed. Customer motivated techniques for determining component functional tolerances are developed. Also, principles of tolerance design are presented and demonstrated. The developed principles are clarified and validated through an original design case study of an electric guitar pickup (electromagnetic transducer) winder. The paper concludes with a discussion of the extensions of this work and future needs for tolerance design research.