Method of manufacturing a tube snap fastening arrangement

A method for fastening a tube to a collar in a furniture arrangement, the method comprising steps of:

• a) providing a hollow tube formed of a material, the tube having a material thickness surrounding the circumference of the tube forming an inner surface towards a hollow of the tube and an outer surface facing radially outwards,
• b) arranging said tube for receiving at least one forming punch in an axial direction of the tube,
• c) punching said tube with the at least one forming punch at a plurality of locations along an inner radial part of an edge portion of the tube in the axial direction of the tube, locally reducing the tube thickness at the plurality of locations along the inner surface of the tube, so that at least of the plurality of locations the material being punched is plastically relocated from the edge portion to a location along the inner surface of the tube, locally forming a snap portion in the form of a flange in the radial direction towards the hollow inside of the tube, wherein a distance along the inner surface of the tube between one snap portion and a second snap portion is different from another distance along the inner surface between the one snap portion and a third snap portion,
• d) providing a collar configured to be arranged on said tube, wherein the collar comprises at least one receiving portion configured to receive said at least one snap portion (11a-h), and
• e) arranging the collar to the tube such that the snap portion engages with said receiving portion.