The members of the National Labor Relations Board, to whom we shall refer as the Board, appeal from an order of the District Court granting a preliminary injunction against the Board in an action by two labor organizations, one the Norwich, Connecticut Printing Specialties and Paper Products Union, Local No. 494, referred to as Local 494, and the other the International Printing Pressmen and Assistants’ Union of North America, AFL-CIO, referred to as the International. The appeal is also from denial by the court of the Board’s motion to dismiss the complaint.

The court enjoined an election directed by the Board to be held in a bargaining unit composed, with certain immaterial exceptions, of the production and maintenance employees of a paper box plant of the Employer, Robertson Paper Box Company, at Montville, Connecticut.1 The basis for the injunction was the claim of Local 494 and of the International that the Employer’s craft employees, to wit, its printing pressmen, cutting and creasing pressmen, apprentices, helpers and related employees consisting of die makers, ink makers and plateroom employees, were an appropriate unit entitled to an election in a unit *630limited to such craft grouping, to the end of being able to vote for or against separate representation on a craft basis, said to be required by Section 9(b) (2) of the Labor-Management Relations Act, 61 Stat. 136 (1947), 29 U.S.C. §§ 141-168 (1958), 29 U.S.C.A. §§ 141-168.

Our question is not whether on the one hand the unit sought by Local 494 and the International, or, on the other hand, the unit fixed by the Board, is the appropriate bargaining unit, but whether the Board in reaching its decision as to the unit disregarded any statutory limitation upon the discretion vested in the Board by section 9(b) of the Act; that is, whether the craft employees were denied a statutory right.2 If the latter, the District Court, under the authority of Leedom v. Kyne, 358 U.S. 184, 79 S.Ct. 180, 3 L.Ed.2d 210, affirming 101 U.S.App.D.C. 398, 249 F. 2d 490, should be upheld in granting the preliminary injunction and in not dismissing the complaint. If the Board merely exercised the discretion available to it, however,3 the District Court was without jurisdiction and erred in enjoining the election. Review of the appropriateness of the unit in that event could be had only in a proceeding in a United States Court of Appeals under section 10(e) or 10(f) of the Act.4 National Biscuit Div. v. Leedom, 105 U.S.App.D.C. 117, 119, 265 F.2d 101, 103, certiorari denied 359 U.S. 1011, 79 S.Ct. 1151, 3 L.Ed.2d 1037.

Appellees claim the Board violated the proviso in section 9(b) (2), supra note 3, which prohibits the Board from deciding that a craft unit is inappropriate “on the ground that a different unit has been established by a prior Board determination * * We are not able to sustain this contention.

In its original Decision and Direction of Election, supporting a statement in the text of the Decision that the production and maintenance employees at the plant, with certain exclusions, were an appropriate unit, the Board in a footnote stated, as set forth more fully in the margin,5 that the Pressmen (the International) had represented this overall unit since 1945 and had also negotiated for a new contract on that basis until the instant petition was filed, though the Pressmen now contended for both a craft *631unit and also a separate other unit composed of the production and maintenance employees other than the craftsmen. Even could this reference to prior history properly be construed as basing the decision on the ground that a different unit had been established by a prior Board decision, violating the restraint imposed on the Board by section 9(b) (2), we think the Supplemental Decision and Second Direction of Election, the one enjoined, cured any such possible violation of that section. The Supplemental Decision and Second Direction of Election called for an election on a plantwide basis, that is, in the same unit as previously. But it relied for the unit determination on evidence, introduced by the Employer at a reopened hearing, to the effect that Local 494, as distinguished from the usual “Printing Pressmen” locals of the International, was not a craft union and had not traditionally organized or represented employees on a craft basis. The Board detailed to a considerable extent the evidence to this effect, including a reference in the International’s constitution to “printing specialty and paper products workers covered on an industrial basis,” and concluded that Local 494 was not a craft but an industrial union. It then stated that additional support for this position was found in the fact that the Local itself had represented the employees here involved on an overall production and maintenance basis for thirteen years prior to the instant petition. The Board relied on American Potash & Chem. Corp., 107 N.L.R.B. 1418 (1954), in which it was held that severance from a plantwide unit will be allowed “where a true craft group is sought and where, in addition, the union seeking to represent it is one which traditionally represents that craft.” Id. at 1422. On the ground that Local 494 was not a traditional representative of a craft union, the Board denied craft severance.

We do not find in the foregoing a violation of section 9(b) (2). The Board decision that the craft unit was inappropriate was not on the ground that a different unit had been established by a prior Board determination, but on the ground that the union seeking the craft unit was not a traditional representative of a specific craft. The mere reference to past bargaining history for “additional support” we think cannot be construed in the circumstances of this case as deciding “that any craft unit is inappropriate * * * on the ground that a different unit has been established by a prior Board determination.”

The soundness of the American Potash doctrine is not before us; for, as we see the matter, that doctrine lies within the discretionary area of Board unit determinations.6 Whether or not the Board has wisely exercised its discretion in formulating or applying the doctrine is apart from the question whether the Board has failed to give effect to a clear statutory command in this case, so as to justify intervention by the District Court in the normal process of determining an appropriate bargaining unit under the Act.

The preliminary injunction is set aside and the case is remanded to the District Court with directions either to dismiss the complaint or to take such further action as is not inconsistent with this opinion.

It is so ordered.