A safety and arming unit (10) for a spinning projectile fuze, which has a fuze body (12) and a bearing body (14), which define a spherical cavity (16) between them, in which a spherical rotor (18) is mounted such that it can rotate, in which rotor (18) a detonator (20) is provided. In order to make the safety and arming unit suitable for fuzes in weapon systems with extremely fast munition feed units, the rotor (18) can be surrounded by a rotor locking ring (28) in the safe position, prevents the rotor (18) from rotating through an acceleration ring (30) and a spring element (32) which connects the acceleration ring (30) to the rotor locking ring (28) in an interlocking manner, with the rotor locking ring (28) being formed with a slot (36) in order that it can be spread open by rotation and centrifugal forces into an open space (34).