Cables laid in wood notches require protection against nails or screws by using a steel plate at least how thick?

• A. 1/8 in
• B. 1/16 in
• C. 1/4 in
• D. 1/32 in

Answer: (B)

When a conductor is laid in a wood notch, it can be damaged by nails or screws from finishes or fasteners. To prevent this, a protective steel plate (a nail plate) is installed over the notch. The plate must be at least 1/16 inch thick. This thickness provides enough resistance to typical nails and screws while keeping installation practical. The other thicknesses aren’t the required standard: 1/32 inch is too thin to reliably stop fasteners, while 1/8 inch or 1/4 inch are thicker than necessary for this purpose.