A system for coupling of units on a substantially rectangular load carrier with four columns arranged in its corners, which system comprises: • a unit in the form of a column with a rectangular profile with four side faces; • a unit in the form of an anchoring piece with a preferably rectangular cross section with four side faces, which anchoring piece is to be arranged on a corner of the load carrier, wherein the anchoring piece and the column are mutually adapted, so that the column and the anchoring piece can be inserted in a mutually sliding engagement along their longitudinal axes, and the anchoring piece and the column comprise side faces with locking parts in the form of at least one cam or a complementary opening thereto, executed in a side face on the column and a side face on the anchoring piece, respectively, which opening and cam have mutually adapted locations and configurations, so that the anchoring piece's and the column's openings and the cam engage, when the column and the anchoring piece are inserted into each other, wherein the column and the anchoring piece comprise two cams (4, 5) or two openings (7, 8) arranged on one of the two units (column or anchoring piece), while two openings (7, 8) or cams (4, 5) adapted thereto are arranged on the other unit, which openings (7, 8) and cams (4, 5) are arranged on the two opposite side faces of each individual unit and preferably symmetrically about the units' longitudinal axes, characterized in that each of the cams (4, 5) is a semi-cutout punching having two bent faces (4′′′ and 4ʺʺ) connected and partly strain-hardened to constitute an inflexible part and a cutout opening (4") formed at an end of the two bent faces (4′′′ and 4ʺʺ). • a unit in the form of a column with a rectangular profile with four side faces; • a unit in the form of an anchoring piece with a preferably rectangular cross section with four side faces, which anchoring piece is to be arranged on a corner of the load carrier, wherein the anchoring piece and the column are mutually adapted, so that the column and the anchoring piece can be inserted in a mutually sliding engagement along their longitudinal axes, and the anchoring piece and the column comprise side faces with locking parts in the form of at least one cam or a complementary opening thereto, executed in a side face on the column and a side face on the anchoring piece, respectively, which opening and cam have mutually adapted locations and configurations, so that the anchoring piece's and the column's openings and the cam engage, when the column and the anchoring piece are inserted into each other, wherein the column and the anchoring piece comprise two cams (4, 5) or two openings (7, 8) arranged on one of the two units (column or anchoring piece), while two openings (7, 8) or cams (4, 5) adapted thereto are arranged on the other unit, which openings (7, 8) and cams (4, 5) are arranged on the two opposite side faces of each individual unit and preferably symmetrically about the units' longitudinal axes, characterized in that each of the cams (4, 5) is a semi-cutout punching having two bent faces (4′′′ and 4ʺʺ) connected and partly strain-hardened to constitute an inflexible part and a cutout opening (4") formed at an end of the two bent faces (4′′′ and 4ʺʺ). wherein the anchoring piece and the column are mutually adapted, so that the column and the anchoring piece can be inserted in a mutually sliding engagement along their longitudinal axes, and the anchoring piece and the column comprise side faces with locking parts in the form of at least one cam or a complementary opening thereto, executed in a side face on the column and a side face on the anchoring piece, respectively, which opening and cam have mutually adapted locations and configurations, so that the anchoring piece's and the column's openings and the cam engage, when the column and the anchoring piece are inserted into each other, wherein the column and the anchoring piece comprise two cams (4, 5) or two openings (7, 8) arranged on one of the two units (column or anchoring piece), while two openings (7, 8) or cams (4, 5) adapted thereto are arranged on the other unit, which openings (7, 8) and cams (4, 5) are arranged on the two opposite side faces of each individual unit and preferably symmetrically about the units' longitudinal axes, characterized in that each of the cams (4, 5) is a semi-cutout punching having two bent faces (4′′′ and 4ʺʺ) connected and partly strain-hardened to constitute an inflexible part and a cutout opening (4") formed at an end of the two bent faces (4′′′ and 4ʺʺ).