The buckle (14) includes a metal body (22) and a snap coupling mechanism (42, 46, 48, 50) for releasable connection of a pair of tongue elements (12) to the metal body (22). The snap coupling mechanism comprises a release button (42) which can be operated by the user to push the tongue elements (12) out of the metal body (22), a locking plate (46) which can assume a locked position in which it retains the tongue elements (12) in the metal body (22) and a released position in which it disengages the tongue elements (12) from the metal body (22), a release member (48) which can be operated via the release button (42) to move the locking plate to the released position, and a pair of sliders (50) for resiliently opposing the insertion of the tongue elements (12) into the metal body (22). According to the invention, the metal body (22) is made as a single sheet metal piece obtained by blanking and folding.