Can mild steel square tubing 33x33mm Square with 2mm walls support a desk-top?

Question

Here is the basic idea: An L-shaped computer desk mounted to the wall with no legs. (Screens will be mounted on the wall.)

This is the Mounting Bracket: The length of the tube will be 22", welded to a section of a 3mm thick mild steel door hinge, that's welded to a 2" 3mm thick section of flat stock. As you can see, there is a Socket Head screw to adjust the angle of the end of the desktop mounting tube.

Above the hinge point of the 2" 3mm thick section of flat stock, there is a slot for mounting the flat stock to the wall.

The next two images show the mounting points (circled in red) for an L-shaped desk and a shelf on the 2 walls. Because it was impossible to get the anchors the same height, you can see the need for the slot in the 2" flat stock.

The next 2 images show the measurements of the materials.

I know the tub can support the 3/4" shelf. What I'm not sure of is its ability to support a 3/4" or 1" desktop that's 2' wide, with no legs.

Answer 1

You don't need legs necessarily but you need to think of what the legs do. They support the cantilevered forces on the outer edges (away from the wall)

Imagine this force as a lever using your wall mounts as a fulcrum. It won't take much leveraged force to pull the screws out.

I recommend that you use angle brackets (the kind that look like triangles) to support the desk. This will still keep legs off the floor at the expense of adding a few spots to bump your knees.