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February 1942. Cincinnati, Ohio. "Aluminum casting. The heads of these heat-treated pistons must be spotted prior to Brinell hardness testing. Young women are employed for this job by a large Midwest aluminum foundry now converted to war production. Aluminum Industries Inc." 4x5 nitrate negative by Alfred Palmer for the Office of War Information. View full size.
Is nothing more than using a belt sander or pedestal grinder to remove the scale and oxide off the as-cast surface, exposing virgin material so they get an accurate hardness reading.
Sorry to disappoint, but those are pistons for trucks or something similar. Aviation pistons tend to be much much shorter with minimal skirts.
for a huge 1000+ H.P. aircraft engines, I would love to know the details!
Those are some lovely ladies working on that spotting job.
Makes me think of the machine works the audience doesn't actually see in Arthur Miller's "All My Sons."
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