What is the collective noun of beam?

There isn't a widely accepted collective noun specifically for beams.

Here are some options depending on the context:

General:

* A set of beams

* A group of beams

* A collection of beams

More specific:

* A truss of beams (for structural beams)

* A bundle of beams (for beams grouped together)

* A frame of beams (for beams forming a framework)

The best choice will depend on the specific type of beam and the context in which you are using the collective noun.