# 100 Objects #2: 60-Degree Screw

An episode of [99% Invisible](https://invisiblenetwork.ai/podcast/394775318), 29 May 2026, 36 min.

Audio: https://mgln.ai/e/2/dts.podtrac.com/redirect.mp3/stitcher.simplecastaudio.com/3bb687b0-04af-4257-90f1-39eef4e631b6/episodes/6d8215c8-36a5-4da7-a005-0e2c1b0258dc/audio/128/default.mp3?aid=rss_feed&awCollectionId=3bb687b0-04af-4257-90f1-39eef4e631b6&awEpisodeId=6d8215c8-36a5-4da7-a005-0e2c1b0258dc&feed=BqbsxVfO

In the early 20th century, nothing quite fit — fire hoses couldn't connect to one another, football teams played with different balls, traffic lights meant different things in different states. Then World War II exposed the deadly cost of incompatibility, and the US quietly imposed a single solution on production lines across the world: the 60-degree screw. Roman Mars and historian Daniel Immerwahr tell the story of a hidden industrial empire, built one standard at a time. A History of the United States in 100 Objects is a production of 99% Invisible and BBC Studios. Subscribe to SiriusXM Podcasts+ to listen to new episodes of 99% Invisible ad-free and a whole week early. Start a free trial now on Apple Podcasts or by visiting siriusxm.com/podcastsplus. Hosted by Simplecast, an AdsWizz company. See pcm.adswizz.com for information about our collection and use of personal data for advertising.

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