When a device box is fastened to a framing member and the screw passes through the box, which location for the fastening screw is acceptable?

• A. The screw must be exactly at the back of the enclosure
• B. It is permitted but must not be more than 6 mm from the back or end of the enclosure
• C. It must be at least 1 inch from the back
• D. It should be on the opposite side

Answer: (B)

When fastening a device box to a framing member, the mounting screw that passes through the box should be located near the rear edge, within a short distance. Specifically, it is acceptable if the screw is no more than 6 mm (about 1/4 inch) from the back or end of the enclosure. This keeps the box securely anchored to the stud without compromising the box walls or internal components, and it provides a reliable hold for the box and any devices installed in it. Placing the screw farther than 6 mm away would reduce securing strength, while options that require being exactly at the back, a full inch from the back, or on the opposite side don’t align with this practical and code-consistent mounting approach.