Is there a minimum plate size to use for webs and flanges?
Flange width and thickness are critical for girder stability during fabrication, transportation, and erection.
- 12" by ¾" is a minimum size recommendation. This minimum size addresses many workmanship tolerances applicable such as flange tilt, bearing flatness, and flange cupping during the web to flange and stiffener to flange welding operations.
- A good rule of thumb used for erection stability is L/b<= 85 for unbraced length.
- Preferred minimum web size for I girders is ½". Welding both sides of stiffeners simultaneously to thinner webs depending on weld size can force a fabricator to apply slower processes, thus adding cost.