Abstract: Internal and external screw thread burnishing assemblies are provided. In the internal screw thread burnishing assembly, diametrically opposed removable cartridges carrying burnishing wheels are received in cavities of a support structure axially movable into the space circumscribed by the internal screw thread. Fluid pressure is utilized to forcibly translate the cartridges radially outwardly to place their burnishing wheels into burnishing engagement with the internal screw thread, with a spring structure resiliently biasing the cartridges toward retracted orientations thereof within the support structure. In the external screw thread burnishing assembly, burnishing wheels are carried on the outer ends of pivotally supported arms which may be pivoted by fluid pressure to drive the burnishing wheels into burnishing engagement with diametrically opposite portions of the external screw thread, with a spring structure resiliently biasing the arms pivotally away from one another.

Abstract: Internal and external screw thread burnishing assemblies are provided. In the internal screw thread burnishing assembly, diametrically opposed removable cartridges carrying burnishing wheels are received in cavities of a support structure axially movable into the space circumscribed by the internal screw thread. Fluid pressure is utilized to forcibly translate the cartridges radially outwardly to place their burnishing wheels into burnishing engagement with the internal screw thread, with a spring structure resiliently biasing the cartridges toward retracted orientations thereof within the support structure. In the external screw thread burnishing assembly, burnishing wheels are carried on the outer ends of pivotally supported arms which may be pivoted by fluid pressure to drive the burnishing wheels into burnishing engagement with diametrically opposite portions of the external screw thread, with a spring structure resiliently biasing the arms pivotally away from one another.