Uploaded February 2025 | Updated September 2026, 1 hour ago

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Today we're digging in to the history of US bolt & nut standards, to try and figure out where those weird /32nd size sockets came from.

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Genius xx/32nd Sockets on Amazon:
amzn.to/4kpBAxs
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Further Reading:
sizes.com/tools/thread_history.htm
progress-is-fine.blogspot.com/2017/01/the-evolution-of-standard-wrench-sizes.html

1864 Franklin Institute Proposal:
archive.org/details/sim_journal-of-the-franklin-institute_1864-05_47_5/page/344/mode/2up

1949 Franklin institute Article:
archive.org/details/sim_journal-of-the-franklin-institute_1949-02_247_2/page/n13/mode/2up

1910 Screw Threads & Gages:
archive.org/details/screwthreadtools00oberrich/page/16/mode/2up

1915 Machinery's Handbook:
books.google.com/books?id=VkEYAAAAYAAJ&printsec=frontcover&dq=editions:-zxxF0uMzIgC

1924 Machinery's Handbook:
google.com/books/edition/_/9-XCPSOFMVgC?gbpv=1

Chapters:
00:00 Parody Intro
00:24 Actual Intro
01:00 The Sellers Standard
02:41 Origin of the 32nd
03:29 Whitworth Naming Convention
04:10 Enter the SAE
04:55 Oddly Marked Wrenches
05:49 The standard gets Unified
06:35 32nd Sizes Today
07:34 Outro