Laterally supported stuff is fairly straightforward, I believe. For laterally unsupported monosymmetric sections I and T sections there's guidance, but for other monosymmetric section it says to use a 'rational method of analysis'
I've normally ended up using the AISC provisions, I believe.
I looked thru the Canadian code and it says that the Cold-Formed code can be used for Class 4 shapes, but the code doesnt offer much guidance on what Class 4 shapes are in terms of width-to-thickness ratios.
The angle is a 2x2x3/16 that is the top chord of a small truss. The top chord cantilevers past just a few inches to pick up a small purlin of sorts.
I want to check the angle for the cantilever bending.
Upon further consideration, single angle brick lintels are an example of that. Never really gave it a lot of thought. I would be inclined to be pretty conservative if the stresses are borderline.
It's pretty common to use angles in bending for small industrial stuff, as well. You see them all over the place for small pipe supports, cable tray supports, and similar short span, low load applications. They're cheap and they're easy to install and fabricate, even if it's being done in the field.
Not sure where you were looking in the Canadian code, but there is lots of information for the width/thickness ratios, although it seems to be scattered throughout the code. See Figure 2-8 on pg 2-28 (in S16-01, don't have the new edition). For legs of angles, a class 3 shape must have b/t less than 200/sqrt(fy). for 350 mPa, an L51x51x4.8 would be class 3, although it is cutting it close.
The CISC website refers to AISC 360 for design of single steel angles in bending:
I don't personally know much about CSA single angles. But, one of our engineers has recently done a lot of work on this subject (for the soon to be released version 11 of RISA-3D). If you contact me privately (via e-mail), I can put you in contact with him directly.
