The present invention concerns a spring core (1, 1a, 12, 13, 17, 18) that may be used in e.g. bed mattresses, chairs or sofas. The spring core (1, 1a, 12, 13, 17, 18) comprises springs placed inside pocket (3). The pockets (3) are placed in a number of rows, which rows of pockets (3) are placed side by side. The spring core (1, 1a, 12, 13, 17, 18) is held in a compressed state by means of at least one cord (5). The at least one cord (5) is formed into braids (6) at opposite outer ends (7) of each row of pockets (3). Further, the at least one cord (4) forms a number of loops (8) on at least one side of each row of pockets (3). By pulling at one free end (10) of the at least one cord (5) the braids (6) and loops (8) are dissolved, allowing the spring core (1) to return to the non-compressed state.