[MarkusWandel]

Except that after the initial model, the PET's case was plastic, or rather, structural foam, with no shielding applied to it all.

[kmoser]

After the initial 2001 model, Commodore used a mix of materials, with some models made of all metal and some of a metal/plastic hybrid (metal base, plastic top), according to this website: https://www.zimmers.net/cbmpics/cbm/PETx/petfaq.html (look for "WHAT MODELS OF THE PET ARE THERE?")

[zabzonk]

Source? Every Commodore PET I've ever come across had a metal chassis. Commodore64s and VICs had plastic ones.

[MarkusWandel]

The chassis (the bottom black part) was always made out of metal. But all the white part above, on the very first PETs (the ones with the rectangular keyboard) it was made out of metal, and on all subsequent ones (with normal keyboard and green-on-black screens) it was made of this plastic material. Source: Personal experience (I'm old).

[buescher]

Interesting. I didn't know that.