46 C.F.R. § 111.01-13 Limitations on porcelain use.
Title 46 - Shipping
Porcelain must not be used for lamp sockets, switches, receptacles, fuse blocks, or other electric equipment where the item is solidly mounted by machine screws or their equivalent, unless the porcelain piece is resiliently mounted.
Title 46: Shipping
PART 111—ELECTRIC SYSTEMS—GENERAL REQUIREMENTS
Subpart 111.01—General
§ 111.01-13 Limitations on porcelain use.
