NLRB v. Columbian Enameling & Stamping Co., 306 U.S. 292 (1939), is a US labor law case where the US Supreme Court held 5-to-2 that the National Labor Relations Act required decisions of the National Labor Relations Board (Board) to be based on substantial evidence. The Supreme Court overturned a ruling of the Board (requiring an employer to rehire striking workers) for not being based on substantial evidence. The Court also held that only the representative of the workers (the union) could issue collective bargaining proposals under the law, and that proposals transmitted by a third party did not trigger the Act's protections or duties.