More recently, I found one of their taps:
They also made vices in Canada. Below, one of mine:
The Henry L. Hanson Company was initially housed in a five-storey building at 25 Union Street in Worcester. Built in 1879 by a wealthy merchant, Stephen Salisbury, it was first used by the Porter Last Company before being occupied by Hanson. For 50 years, Hanson made taps and dies there that gained world-wide fame for their quality. They eventually made a variety of hand and power tool accessories under names such as "Handy" as well as "Ace" and sold these through retail hardware outlets, mass merchants, and automotive and industrial channels. In 1975, the company moved to a modern facility in the same city. At some point, the company became a part of the Irwin tool empire (now a part of Newell Rubbermaid), where the name is still used as a brand. Unfortunately, according to comments I've read on various web forums, the taps and dies under this brand name are now made in China and are considered to be of very poor quality.
The city of Worcester was once a huge manufacturing centre, especially after 1828 with the completion of the Blackstone Canal which linked the city to Providence. The Boston-Worcester railway, established in 1835, also helped build the city's fortunes. At its height, local companies made machine tools, wire products, power looms, ice skates, and corsets. However, its industrial decline began after World War II. The space race provided a brief respite, as the rocket pioneer Robert Goddard was a native and obtained his post-secondary education in the city's universities. During the Apollo moon landing in 1969, the David Clark Company of Worcester designed the "Snoopy cap", the communications carrier assembly, that transmitted Neil Armstrong's famous first words from the moon. Other local companies also made the legs of the Apollo 11 Lunar Excursion Module, forgings for the spacecraft, and superinsulation and ceramic coating for the rocket nozzles.
Worcester is now strenuously attempting to re-invent itself. Today, the old Hanson factory is the home of Max Silverman's Toolhouse restaurant, where you can enjoy a meal in the presence of some of the original Hanson machinery!
Update, Nov 2020; A reader sends in pictures of his made in USA Henry Hanson Ace tap and die set, still in regular use.