Petitioner, National Labor Relations Board, petitioned this court to enforce its order issued against May Aluminum, Incorporated, respondent herein. The Board found that respondent was guilty of unfair labor practices in that it violated § 8(a) (3) of the National Labor Relations Act by discharging its employee, Thelton Perkins, because of his union activity, and violated § 8(a) (1) of the Act by interfering with, restraining, and coercing employees of the company in the exercise of rights guaranteed to them by the Act. Respondent contends that the record before the Board considered as a whole fails to support the Board’s conclusions that respondent was guilty of violations of the Act. We have examined the record of the testimony before the Trial Examiner upon which the Board based its order. It would serve no useful purpose to sift this testimony out in detail. The matter of the credibility of the witnesses is not for this court to pass upon. This is a function of the Trial Examiner and of the Board. We are satisfied that upon the record considered as a whole there is substantial evidence to support the findings of the Board as to the unfair labor practices in question. The order of the Board will be

Enforced.