Abstract: A screwcapping head for applying prethreaded closures onto prethreaded containers is disclosed having a hysteresis clutch. The screwcapping head includes a housing adapted to be secured to a rotatable drive spindle and a quill mounted in the housing for free rotation thereto. The screwcapping head also includes a hysteresis clutch having a pair of permanent magnetic rings secured to the housing and a disc of hysteresis material secured to the quill and sandwiched between the pair of permanent magnetic rings. The clutch is capable of slipping after the application of a prethreaded closure onto a prethreaded container at a desired torque value while eliminating the torque reversal feature inherent in synchronous clutches.