X-ray computed tomography for dimensional measurements of threaded parts

X-ray computed tomography (CT) is and advanced measuring technique capable of performing holistic dimensional verification of both internal and external threaded elements. The contactless and non-destructive nature of CT measurements makes them suited for evaluating also screw threads and threaded features that are internal, small in size, or made of easily deformable materials, overcoming the limitations of conventional contact and optical measuring techniques. This work presents a CT-based methodology for measuring the geometry and local form errors of threaded products applied to (i) additively manufactured metal dental implants (characterized by significant form errors and complex surface topography) and (ii) injection molded polymeric threaded components (fragile, deformable and characterized by high form errors). The accuracy of CT dimensional measurements is investigated through comparison with reference measurements.