The bend radius is measured relative to the outside diameter of which wire?

• A. Smallest wire
• B. Average wire
• C. All wires combined
• D. Largest wire

Answer: (D)

The bend radius is governed by the largest outside diameter in the bend. Why? Because the outer surface of the bend is set by the wire with the biggest insulation thickness and diameter. If you bend using a radius that matches a smaller wire, the larger wire would be forced into too tight a curve, risking insulation damage or conductor stress. So when routing multiple wires together, you choose a bend radius that accommodates the largest wire’s outside diameter to ensure all wires clear the bend safely. The smaller wires will fit within that same bend without issue.