Previously, we noticed the NEC vaguely defines "bonded (bonding)." Article 100 doesn't, for example, specify how conductive the bonding jumper must be. But throughout the NEC, and especially in Art. 250, we find the answer embedded in the requirements for conductors used to bond things together
Grounding and Bonding, Part 3
Article 100 doesn't specify how conductive the bonding jumper must be.