William Sellers Screw Thread Standard @ the Franklin Institute - Philadelphia, PA
N 39° 57.482 W 075° 10.365
18S E 485245 N 4423113
A plaque inside the service entrance (to the left of the main entrance) & across from the cafeteria on the bottom floor marks this historic ASME site. The plaque tells the story & marks the site for the first US system of standardized screw threads.
Waymark Code: WM7B52
Location: Pennsylvania, United States
Date Posted: 09/29/2009
Views: 4
The service entrance is just to the left of the main stairs leading to the main entrance. When you go through the doors, make an immediate left, go through the entranceway (you will see two mosaic tile murals on your left) and the cafeteria will be on your left, continue down the hall and you will see a wall on the left. This is where the plaque is. Opposite this plaque is a penny smasher.
This site is marked as #234 on the ASME site. To find the ASME web page simple go HERE
The top plaque reads:
Historic Physics Site
Register of Historic Sites
American Physical Society
2005
The bottom plaque reads:
MECHANICAL ENGINEERING
HERITAGE SITE
United States Standard Screw Threads
At the Franklin Institute - 1864
In 1864, an American maker of machine tools, William Sellers developed a comprehensive system for the design of screw threads for machine bolts and hex nuts. Within the year, Sellers system had been endorsed by Philadelphia's Franklin Institute, then America's leading research and development organization in mechanical engineering. Over subsequent decades the Sellers or Franklin Institute threads became a national standard. This rationally elegant, yet simple system of fasteners boosted productivity.....
From the ASME web site:
"William Sellers (1824-1905) of Philadelphia was inspired by Great Britain’s adoption of a comprehensive system of screw threads promulgated in 1841 by that nation's leading maker of machine tools, Joseph Whitworth (1803-1887). He understood the value of Whitworth's standard, a clear improvement over the various "mongrel" threads that U.S. machinery makers used, but Sellers decided to improve upon Whitworth's approach, creating a system of threads adapted to U.S. needs.".