There's a story behind this picture, and I'd like to share it with you.
Back in the 70's, offices were changing. No longer did the typical desk have but a typwriter and - maybe - a pencil sharpener. Computers were coming; word processors and plug-in calculators were common. Even the simplest desk required several receptacles.
So, the 'power strip' came on the market. None of these were UL-listed, simply because UL refused to do so. It was felt that installing a power strip would lead to an NEC violation: that is, more receptacles than the code allowed on a circuit.
Within the offices of a certain testing lab, the staff faced the same problems as everyone else: not enough receptacles. Well, they certainly were not about to buy a non-listed product! Oh, no .... they had their maintenance guys make something. This is a pic of what they came up with:
They put a single piece of metal into a large punch with a die on it. The die holds the metal by the edges while the rest of it is stamped into the shape of the die. The tabs for the screws are bent over in a separate operation, while the knockouts are punched 'almost' through, with the exception of the little part that holds it in place.
If it's a complicated part, it may go through several separate dies to get to the finished product.
Some of the auto part stampings when I was working at Ford went through as many as 5 dies to get to a finished part, with some of those dies having moving parts so that the steel wouldn't get stuck on the bottom part of the die.