Free AutoCAD reinforcement drawing symbols (DWG): bars, hooks, bar shapes, welded fabric

About the standard

ISO 3766 sets the rules for simplified representation of reinforcement in concrete structures: how bars, bends, hooks, sections, bar sets, welded fabric and prestressed reinforcement are drawn, how bars are marked, and the bar shapes of the bending schedule. This library follows those rules.

The blocks are our own drawings, not copies of the standard, and the library is not certified. The layer layouts of the standard's tables, the schedule tables and the complete bar shape catalogue are not in the library. Check the blocks against the standard and the drawing rules your office or country uses.

Frequently asked questions

Which bar shapes are in the library?

The fifteen shapes of the bending schedule table: the straight bar and the shapes with one, two or three bends, with a closed form and with a spiral, in 00, 11, 12, 13, 15, 21, 25, 26, 31, 33, 41, 44, 46, 67 and 77. Each is drawn with its dimension letters, and all but shape 33 also with end hooks.

How do I mark a bar on the drawing?

Use the bar marking block: it shows the bar mark and the bar note, for example 19 bars of 20 mm at 200 mm spacing, and the mark circle or the mark oval for the number of the bar. The bar note and the bar mark are attributes, so you change them with a double click.

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. Please do not redistribute or resell the library; see the library terms.

Does it include welded fabric and prestressed reinforcement?

Yes: welded fabric in plan, in rows and in section (also simplified), and prestressed tendons with their sections, stressing and fixed end anchorages and splices. The mat type, wire sizes and sheet numbers are attributes.

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.