Ironworkers Local Union 401 is a chapter of the International Association of Bridge, Structural, Ornamental, and Reinforcing Ironworkers. Ironworkers Local 401 is affiliated with the AFL-CIO and the Philadelphia Building and Construction Trades Council.

Members of Ironworkers Local 401 are highly skilled craftsmen serving the many types of contractors in the “Union Ironworking Industry”.

Local 401 Ironworkers complete a four year apprenticeship and are trained in skills such as the erection of structural steel, miscellaneous steel, metal curtain-wall and window wall systems, precast concrete structures, fences, towers, pre-engineered metal buildings, and other steel structures.