Abstract: A cutting blade assembly (8) for a rotary mower. The assembly (8) comprises a blade carrier (1) and four swing-back cutting blades (10) (only one of which is shown). The blade carrier (1) has a substantially planar discoid body (2), a mount (3) for mounting the body (2) to a drive shaft assembly (not shown) of the mower, four airflow passages (5) extending through the body (2), and a blade connecting mechanism (6) for connecting the blades (10) to the body (2). The body (2) is made of laser- or plasma-cut, high-strength steel (Bisplate 80™) having a thickness in the order of 5 to 6 mm.