In American Metal we held, inter alia, that where a duty to bargain arose from a collective bargaining agreement rather than from statutory obligations an NLRB finding of an appropriate bargaining unit was not necessary as a precondition to contract negotiations.
Holding that notwithstanding the expiration of the original labor contract, the employer was bound by a renewal contract issued by the arbitration panel according to the interest arbitration clause
In Huggins Sheet Metal and in Williams, the parties had reached an impasse in negotiations on the new agreement, and the unions sought interest arbitration under their respective collective bargaining agreements.