Abstract: The partition wall units include panels with mitered tubular frame strips, posts, raceways which also can be adapted for baseboards, and covering edge strips. Most of these units include a groove along an outer edge into which are removably mounted interlocking or interhooking key members having uniform C-shaped cross-sections. These C-shaped cross-section key members on adjacent edges slideably engage each other to form cylindrical apertures between the two interhooked C's. Self-tapping screws are then screwed into these cylindrical apertures near the ends of the adjacent strip for locking the two units together. The substantially rectangular tubular frame strips around the panels have mitered joints which are connected by a pair of longitudinally complementary angle blocks with complementary grooves along their legs between their abutting surfaces.