6 inch 152 mm Cast iron Inspired Floor Vent

Designed as a floor vent cover for air ducts or drains. Fits a 6 inch or 152mm  square hole. Since this is a designed to go on the floor i designed it to be strong enough for my 200lb self to step on it. I would try and avoid excess pressure but it is quite strong. 

The holes are sized to use drywall screws for mounting, as I wanted to use something black. #8 Flush head screws should also work. 

Scaling of this model should work alright for other applications for small size changes but since the screw holes would be effected I have included a version without screw holes. 

If strength is not an issue reducing walls to 2 and reducing height of the model dramatically reduces filament usage