Free ASME B16.5 pipe flanges for AutoCAD (DWG): weld neck, slip-on and blind

About ASME B16.5 and the dimensions

Flange diameter, raised face diameter, thickness, bolt circle and bolt holes follow the tables of ASME B16.5; they agree in several published tables. The raised face is 1/16 in for Class 150 and 300, included in the thickness, and 1/4 in for Class 600, added to it. Hub diameter and length come from the published weld neck and slip-on tables.

The blocks are our own drawings, not copies of the standard, and the library is not certified. Dimensions are nominal, without tolerances. Slip-on flanges of Class 600 in NPS 3-1/2 are not in the published tables and are left out. Check the dimensions against the edition of ASME B16.5 your project uses.

Frequently asked questions

Are these flanges to ASME B16.5?

Yes. Flange diameter, raised face, thickness, bolt circle and bolt holes come from the tables of the standard, and they agree in several published tables. They are nominal drawing dimensions, without tolerances.

Which bore do the weld neck flanges have?

The bore of the standard wall: STD for Class 150 and 300, XS for Class 600. A weld neck flange is bored to match the pipe, so change the bore if your line has another schedule.

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 flange list from my drawings?

Export the flange blocks of all drawings to Excel with BlockSync: one row per block with DESIGNATION, type, class, material and quantity. Total them with a pivot table to get a flange list.

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.