Metal frame construction

A metal door frame, comprising

• first and second upright channel members each having a web and two parallel side flanges,
• a plurality of cross channel members each having a web and two parallel side flanges, said upright channel members being disposed in mutually parallel relationship,
• said cross channel members being respectively disposed in perpendicular relationship to said upright channel members,
• the end portions of said cross channel members being disposed within respective ones of said upright channel members abutting the webs of said upright channel members and with the faces of the adjacent said flanges of said upright and cross channel members being in mutual engagement,
• said upright channel members each having a plurality of tongue portions integral with said side flanges and extending through respective openings in the adjacent ones of said side flanges of said cross channel members,
• said tongue portions being curled under said side flanges of said cross channel members to secure said cross members to said upright members and to hold the ends of said cross channel members in abutment with the webs of said upright members.