View Full Version : X Rail I beam thickness??

Tue 17 May 2011, 10:17
Have been looking for cheap c channel or I beams and have come empty handed on the c channel but there are plenty of cheap I beams around. My question is regarding the thickness of the web, is 1/4 inch thick too thin on a 8" beam? there are also 12" beams with the 1/4 web. Would the 1/4 web 12" work although I would have to deal with raising the cutting surface.

Tue 17 May 2011, 18:26
The C channel specified for the machine can be either C 8" x 11.5#/Ft or higher which has a modulus of 8.14 in the x-x plane.
The W or S shape "I beam" of that height and equal weight does have a section modulus in the x and y that meet or exceed that requirement. For example a W12x16# has a modulus of 14.9.

This is only one part of the criterea where bending moment, shear and 1/360 span formula's apply...but in the spirit of the Mechmate, your "found" steel sections will be fine.

If any of the qualified engineers in the room disagree....please advise. I only play an engineer on TV! :)