The tie comprises a strap (1) extending along a first longitudinal axis (X) between two end parts (2, 4) that have a female part (3) and a male part (5) for a fastening system, and a locking member (6) for locking said male part (5) in said female part (3) when the male part is inserted into the female part. Said locking member comprises a strip (6) and a slot (7) passing through said male part (5), into which said strip (6) is intended to be inserted along a second axis (Y) approximately perpendicular to said first longitudinal axis (X). A locking means (10, 11, 13, 14) for locking the strip (6) in the slot (7) is provided in such a way as to prevent the strip (6) from sliding inside the slot (7) in an insertion direction and in the opposite direction along said second axis (Y) after the strip (6) has passed a certain position of insertion into the slot (7) in said insertion direction.
