No on the industrial machines the pin is in the coupling between the gear box and lead screw, On our 14 X 60 monarch lathes it was a 3/16 pin from leaded steel on these small lathes that would be sized down to maybe .020 dia. I know of one high school shop the instructor replaced them with deralin pins. Students sheared a lot more but a lot less broken tooling and other damage. Those plastic gears aren't that expensive usually, and are a good safety.