Abstract: An interlocking structural element is disclosed for the construction of cabinets and enclosures, including modular cabinets and enclosures. Four equal lengths of the interlocking structural element can be used in conjunction with simple flat rectangular panels to fabricate a single enclosure. Additional lengths may be used to fabricate an enclosure with multiple compartments. The interlocking structural element may be fabricated by extruding metal or other material such as plastic. The element incorporates slots for easy mounting of shelves, printed circuit boards or other objects within the enclosure.