An assembly comprising: a box component that is part of a stator of a drilling motor; and a pin component for a drill string, wherein the box component and the pin component are coupled together, the pin component comprising: a threaded portion having a first end and a second end opposite the first end; an extended portion extending axially in a first direction from the first end of the threaded portion, wherein the extended portion comprises a first outer surface comprising a first diameter, wherein the first outer surface is positioned in and coupled to an inner area defined by the box component by an interference fit to absorb stress from the threaded portion during a bend for a wellbore drilling operation; a recess extending axially in a second direction from the second end of the threaded portion, wherein the recess receives a box-extended portion of the box component externally to the pin component, wherein the recess comprises a second outer surface comprising a second diameter, wherein the second diameter is greater than the first diameter, and the first outer surface and second outer surface are parallel; and a body extending axially in the second direction from the recess, wherein the body comprises a third outer surface comprising a third diameter, wherein the third diameter is greater than the second diameter. a box component that is part of a stator of a drilling motor; and a pin component for a drill string, wherein the box component and the pin component are coupled together, the pin component comprising: a threaded portion having a first end and a second end opposite the first end; an extended portion extending axially in a first direction from the first end of the threaded portion, wherein the extended portion comprises a first outer surface comprising a first diameter, wherein the first outer surface is positioned in and coupled to an inner area defined by the box component by an interference fit to absorb stress from the threaded portion during a bend for a wellbore drilling operation; a recess extending axially in a second direction from the second end of the threaded portion, wherein the recess receives a box-extended portion of the box component externally to the pin component, wherein the recess comprises a second outer surface comprising a second diameter, wherein the second diameter is greater than the first diameter, and the first outer surface and second outer surface are parallel; and a body extending axially in the second direction from the recess, wherein the body comprises a third outer surface comprising a third diameter, wherein the third diameter is greater than the second diameter. a threaded portion having a first end and a second end opposite the first end; an extended portion extending axially in a first direction from the first end of the threaded portion, wherein the extended portion comprises a first outer surface comprising a first diameter, wherein the first outer surface is positioned in and coupled to an inner area defined by the box component by an interference fit to absorb stress from the threaded portion during a bend for a wellbore drilling operation; a recess extending axially in a second direction from the second end of the threaded portion, wherein the recess receives a box-extended portion of the box component externally to the pin component, wherein the recess comprises a second outer surface comprising a second diameter, wherein the second diameter is greater than the first diameter, and the first outer surface and second outer surface are parallel; and a body extending axially in the second direction from the recess, wherein the body comprises a third outer surface comprising a third diameter, wherein the third diameter is greater than the second diameter.