Cast iron has poor tensile strength. And U.S. made is hard to tell any more and may not help. We make some junk here too.
There is a small manufacturing town in Taiwan named Usa. The products are then labelled "Made in USA."
I once owned an older Jaguar (XK-140) that had a brass drain plug. I wanted to change the oil and was far from my tools so I went into a convenience store and bought an adjustable 12" wrench from a bin of very inexpensive tools. It was stamped, "Ajastable Angle Wrench". Entertaining.
Upon applying it the the drain plug, the brass plug damaged the iron wrench beyond salvage. It was dead soft iron with no carbon. Perhaps suitable for an electrical transformer of an electromagnet.
There are minimums of suitability and you often get what you pay for.
If you think you are too small to make a difference, try sleeping with a mosquito.
Dalai Lama