Which materials are permitted for use with IMC fittings and enclosures?

The correct choice indicates that both steel and aluminum materials are permitted for use with Intermediate Metal Conduit (IMC) fittings and enclosures. IMC is a type of rigid metal conduit that provides protection for electrical wiring in various applications.

Using both steel and aluminum expands the versatility of IMC installations, catering to different environmental conditions and project requirements. Steel is known for its strength and durability, making it suitable for areas with potential mechanical damage. On the other hand, aluminum is lighter and resistant to corrosion, which can be particularly beneficial in marine environments or when weight is a concern.

Each material may have specific applications where its properties are advantageous. Therefore, allowing both materials promotes adaptability in installation practices and compliance with various installation conditions outlined in the National Electrical Code (NEC).