Steel Channel Labeling (US)
 

Gerald,

I am about to buy steel. If anyone is as confused about steel channel labeling as I was, this might help.

Channel is used for these two applications:

- 10 10 322 Main Longitudnal Beams where the drawing asks for channels 2 to 4" wide and 6 to 8" tall, where the metric guide mass is 21kg/m [14 lb/ft]. From that table, C7x12.25 to C8x13.75 (4 sizes) will all be okay. The variance in "bend resistance" ranges from 24.2 to 36.1, but this a supported beam where other factors come into play.

- 10 10 302 Cross Bearer where the drawing asks for channels 1.5" wide and 3" tall, where the metric guide mass is 7kg/m [4.7 lb/ft]. From that table, all the C3's will be okay. The variance in "bend resistance" ranges from 1.66 to 2.07.

If building on a very tight budget, go for the cheapest (lightest). Used steel is NOT inferior to new steel for this application.

Marc, did that supplier have a page on "parallel flange" channels? They are easier to bolt through, for those wanting to do this.

I'll check and re-post if I find it. A couple of weeks ago, when J.R. first posted his picture of his home-made bevel washers, I found sources of them online. I believe that they are made for exactly this purpose. Example - http://www.chicagohardware.com/catalog/31_washers.pdf

Yes, the bevel/taper washers are a solution, but they are a pain to hold square while the joint is tightened.