Conversation

Steel produced prior to World War II is highly sought after, and usually sells for a premium. The reason why may surprise you. It's not due to any perceived higher quality than steel produced later -- not in the ordinary sense, anyway.

The issue is that steel smelted after WWII pretty much all contains tiny amounts of radioactive contamination from above ground nuclear tests, which were common until the signing of the nuclear test ban treaty in 1963.

While the amount of radiation in that steel is extremely low, it's high enough to interfere with some very high precision instrumentation. So manufacturers of some affected equipment want that "old steel" to use instead.

Since the global atmospheric contamination levels associated with those tests has been dropping over the decades, it's a decreasing problem for newly produced steel.

Still, a large find of old steel, like a sunken pre-WWII battleship for example, is still much valued due to these issues.

So now you know.