Hi gain-concern,

Perhaps use the RS Object Tag> Particles, with the MoGraph Matrix, to get these detailed results without any render bottleneck.

I have used a simple material, but the key is that the Noise is set to World like the Zink-coating would look with that Grating.

Render the scene, and you should notice how fast it is.
CV4_2024_drs_23_RSgr_02.c4d
Two objects are available, beveled or simple.

Screen Shot 2023-11-22 at 1.35.53 PM.jpg
Screen Shot 2023-11-22 at 1.47.17 PM.jpg
As a side note:
My initial tip with Bevel was based on the guessing (missing the image) that it was perhaps based on the German term "Grat" (English Burr). Before I studied Architecture, I went to a Metal/Electric school, and in our practical assignments, we had to get the Grat (Burr) off the Steel edges. (entgraten).
Since I have gotten questions from all over the world in the past two decades, I often have to go with a guess. But yes, your term was absolutely correct.

All the best