Free AISC channels and angles for AutoCAD (DWG): C shapes and L angles

About the AISC tables and the dimensions

The dimensions come from the AISC shape tables. The radii are not listed there, so they are derived: the channels have the 1:6 flange slope with the root radius taken from the k distance, the angles a root radius of k − t and a toe radius of half of it. The area of each drawn outline agrees with the table area within about 1 to 2 %.

The blocks are our own drawings, not copies of the AISC tables, and the library is not certified. Dimensions are nominal. Check them against the edition of the AISC Steel Construction Manual your project uses, and use the manual or your supplier for design values.

Frequently asked questions

Are these shapes to the AISC tables?

Yes. Depth, leg and flange sizes and thicknesses come from the AISC shape tables, and the weight per foot and the area are the table values. The radii are derived, because the tables do not list them.

Can I use the blocks in a millimetre drawing?

Yes. The blocks are drawn in inches, so insert them with a scale factor of 25.4 in a drawing in millimetres. In a drawing in inches insert them at scale 1.

Can I use the symbols in commercial projects?

Yes. They are free to use and modify in your own projects, including commercial ones. They are provided as is, without warranty.

How do I get a steel list from my drawings?

Export the shape blocks of all drawings to Excel with BlockSync: one row per block with DESIGNATION, length, quantity and weight per foot. Multiply and total them with a pivot table.

Can I change a symbol or add attributes?

Yes. Open the DWG, edit a block with BEDIT to change it or add attributes, and save. To update drawings that already contain the block, run ATTSYNC or replace the block. Make a backup first: attribute values can be lost if ATTSYNC is used carelessly.

Where do I find a ready-made set of these symbols for AutoCAD?

AutoCAD itself ships only a small set of sample blocks, so a full symbol set has to come from a library. Download the ZIP on this page and open the DWG: every symbol is a block. Insert one with INSERT (Blocks palette, Libraries tab, then pick the DWG) or drag it from DesignCenter (ADCENTER). You can also download a single symbol on its own.