Bonding connections for signs must not be made with sheet metal screws.

• A. True
• B. False
• C. Depends on metal type
• D. Only for outdoor installations

Answer: (A)

Bonding is about giving metal parts a reliable, low-impedance path to the equipment grounding conductor so that any fault can quickly trip a disconnect and keep metal surfaces at safe earth potential. For signs, the metal enclosure must be bonded to the circuit’s grounding path. Sheet metal screws aren’t suitable for this purpose because they’re not designed to provide a durable electrical bond; they can loosen, corrode, or lose contact over time, breaking the bond and defeating the safety purpose. The proper method is to use a listed bonding jumper or clamp and attach it with hardware designed for bonding, connecting the sign’s metal frame to the equipment grounding conductor as required. That’s why bonding connections for signs should not be made with sheet metal screws.