Yes it is.
An example showing how to use the Lead Screw Joint is contained in the Simscape Multibody Parts Library, which is available on the MATLAB Central File Exchange. It provides parameterized parts for Simscape Multibody, gear assemblies, MATLAB code for extrusions. A screenshot of a model contained in the submission (>> sm_lead_screw_actuation_torque) is shown below.
The subsystem "Screw" contains two Solid blocks that form the screw and a flange that the motor can rotate. The Revolute Screw joint lets part Screw spin about a single axis. The Lead Screw Joint constrains part Slider to move when the Screw turns. The Prismatic Slider joint permits the slider to only slide.
--Steve
