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Code Q&A: NEC Requirements for Bending Radius of MC Cable

Dec. 14, 2023

Test your knowledge of the NEC.

Q. What is the minimum bending radius of MC cable?

See answer below.

A. According to Sec. 330.24, bends must be made so the cable will not be damaged, and the radius of the curve of any bend at the inner edge of the cable must not be less than that dictated in each of the following instances:

(A) Smooth-Sheath Cables

(1) Smooth-sheath Type MC cables are not permitted to be bent so the bending radius of the inner edge of the cable is less than 10 times the external diameter of the metallic sheath for cable up to ¾ in. in external diameter.

(B) Interlocked- or Corrugated-Sheath Armor. Interlocked- or corrugated-sheath Type MC cable is not permitted to be bent so the bending radius of the inner edge of the cable is less than seven times the external diameter of the cable.

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About the Author

Mike Holt

Mike Holt is the owner of Mike Holt Enterprises (www.MikeHolt.com), one of the largest electrical publishers in the United States. He earned a master's degree in the Business Administration Program (MBA) from the University of Miami. He earned his reputation as a National Electrical Code (NEC) expert by working his way up through the electrical trade. Formally a construction editor for two different trade publications, Mike started his career as an apprentice electrician and eventually became a master electrician, an electrical inspector, a contractor, and an educator. Mike has taught more than 1,000 classes on 30 different electrical-related subjects — ranging from alarm installations to exam preparation and voltage drop calculations. He continues to produce seminars, videos, books, and online training for the trade as well as contribute monthly Code content to EC&M magazine.