Abstract: The invention relates to a pneumatically powered nut runner having an axial swivel interposed the housings of the air motor and gear reducer which permits radial repositioning of the gear reducer housing relative to the air motor housing. A torque reaction bar is affixed to the gear reducer housing and is thus also radially repositionable relative to the air motor housing. This repositioning capability facilitates adjustment of the reaction bar so that it contacts a bracing point without necessitating the radial repositioning of the air motor housing. When torque is applied to a fastener, nearly all reaction torque is taken by the torque bar and none is transmitted to the operator.