"Elliot G" fired this volley in
m:

I can affirm by experience that a 6" standard I-beam, 16' between
concrete walls, will support a 1300 pound welding machine in the
center.



Extrapolate from this, if you can (I can't G). I know from having
built a press around one, that 8" x 8" beam with 3/8" web and 3/8"
flanges will take 27,000lb at the center of a 16" span, without any
_visible_ deflection. And that's on the flat (web vertical), rather
than with the bending moment on the flanges.

LLoyd