Hi Jorge,
That looks to be a revolved arc feature with the side wall drafted or cut at given angle.
Modeling should reflect the machining process. You are also missing the groove dimensions
that the thumb screw engages into. Your drawing indicates they are cut to mate the crown of the lead screw.
So you need the position for the lead screw center, the pitch, number of threads etc. The dimensions shown
in Detalle C are hardly functional.
cut-extrude OR draft OR rotate face OR extrude a surface and replace face
and there are probably a few more options.