The chief judge of U.S. District Court here ruled yesterday that certain job selection criteria used by the Washington area's sheet metal workers union and the employers discriminate against blacks who apply for positions in an apprenticeship program.

Judge William B. Bryant said that the sheet metal workers advertisement of a high school degree requirement deters black applicants from seeking placement in the apprenticeship program. Bryant also ruled that black applicants were treated differently in job interviews than are other applicants.

Bryant ordered the union, an association of sheet metal contractors and a joint committee which overseas apprentice selection to immediately eli-prentice selection to immediately eliminate the requirement that applicants have a high school diploma or the equivalent; that they do not rely on arrest inquiries in the selection process, and not consider subjective personal interview scores in their section.

In a 50-page opinion, Bryant ao barred the three groups from acting on any pending apprenticeship applications until they comply with those provisions of the court order. He also directed the groups to take affirmative steps to notify the black community "of the elimination of these discriminatory hiring criteria . . ."

The joint apprenticeship committee, made up of representatives from Sheet Metal Workers Local 102 and the D.C. Chapter of the Sheet Metal and Air-Conditioning Contractors National Association, operates a four-year apprenticeship program.