National Union of Sheet Metal Workers, Coppersmiths, Heating and Domestic Engineers

The National Union of Sheet Metal Workers, Coppersmiths, Heating and Domestic Engineers was a trade union in the United Kingdom and Ireland.

The union was founded in 1920 as the National Union of Sheet Metal Workers and Braziers with the merger of a number of unions, including the General Union of Tinplate Workers. It merged with the competing National Society of Coppersmiths, Braziers and Metal Workers in 1959, renaming itself the National Union of Sheet Metal Workers and Coppersmiths. Following its 1967 merger with the Heating and Domestic Engineers' Union, it took its final, lengthy name.

In 1983, the union merged into the Technical, Administrative and Supervisory Section.