Here's a dynamic block for Hollow Structural Steel in Standard US Sizes,with a table of standard sizes. I created this for use in the construction of Steel Structures with square HSS and it has been very useful. To be used for elevation views.
There are Visibility States, ranging from 1/8" - 1/2" Thickness and the Width and Length are adjustable by grips. Also very useful when creating a parts list while using the EATTEXT command.
I hope you find it useful.