Hello
I am a draughtsman in a concrete company and I would have liked to know the procedure to follow to show the weights of parts in a nomenclature.
The walls, the top slab and the bottom slab form an assembly and the material is already made of concrete.
Thank you in advance
Kind regards
Gaëtan
Hello
Normally, the default BOMs of solidworks offer you a column with the weight.
Be careful with the multi-body design, in this case the management of the 3D is different and the nomenclature too, it seems to me. The part will have to be dissolved into the options when inserting the BOM on the plan.
My questions
Do you have an assembly with the parts (concrete volume, or other) corresponding to each line of your nomenclature?
Or did you build your 3D in a single part file, i.e. multibody?
Excuse me, you already answer my questions.
In your case an assembly, you should know that solidworks manages BOMs via custom properties. These are normally created and you don't have to do anything.
When inserting the BOM on your drawing, if the weight column exists, it will appear.
The column doesn't exist (surprising but good!)
You should know that the solidworks and Excel bills of materials work a bit similarly. Right-click insert column. Apply the mass property to the column
The mass property does not exist.
Open Part, Open Custom Properties. Create a MASS line, in the second box it already offers you choices including MASS.
Thank you both very much, so the subject can be closed 
I take advantage of this subject to bounce back on an associated problem that I have encountered several times.
Let's imagine an assembly with several parts. Some parts are in " kg " units and others in " gr "
I noticed that in the assembly BOM, there are often unit errors because SLDW displays everything according to the mass unit of the ASM.
Thank you
