Carl Edvard Johansson (1864–1943) was a

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

inventor and scientist. Johansson invented the

gauge block Gauge blocks (also known as gage blocks, Johansson gauges, slip gauges, or Jo blocks) are a system for producing precision lengths. The individual gauge block is a metal or ceramic block that has been precision ground and lapped to a specific ...

set, also known as "Jo Blocks" ("Johansson gauge blocks"). He was granted his first Swedish patent on 2 May 1901, Swedish patent No. 17017 called "Gauge Block Sets for Precision Measurement". He formed the Swedish company CE Johansson AB (CEJ AB),

Eskilstuna, Sweden Eskilstuna () is a city and the seat of Eskilstuna Municipality, Södermanland County, Sweden. The city of Eskilstuna had 67,359 inhabitants in 2015, with a total population of 100,092 inhabitants in Eskilstuna municipality (2014). Eskilstuna h ...

in 1911. The first CEJ gauge block set in America was sold to Henry M. Leland at

Cadillac The Cadillac Motor Car Division () is a division of the American automobile manufacturer General Motors (GM) that designs and builds luxury vehicles. Its major markets are the United States, Canada, and China. Cadillac models are distributed ...

Automobile Co. around 1908. At the end of his career, in 1923, Johansson started to work for

Henry Ford Henry Ford (July 30, 1863 – April 7, 1947) was an American industrialist, business magnate, founder of the Ford Motor Company, and chief developer of the assembly line technique of mass production. By creating the first automobile that ...

at the

Ford Motor Company Ford Motor Company (commonly known as Ford) is an American multinational automobile manufacturer headquartered in Dearborn, Michigan, United States. It was founded by Henry Ford and incorporated on June 16, 1903. The company sells automobi ...

, in

Dearborn, Michigan Dearborn is a city in Wayne County in the U.S. state of Michigan. At the 2020 census, it had a population of 109,976. Dearborn is the seventh most-populated city in Michigan and is home to the largest Muslim population in the United States per ...

. Ford bought the entire American company, CE Johansson Inc., that he had established 1918 in

Poughkeepsie, New York Poughkeepsie ( ), officially the City of Poughkeepsie, separate from the Town of Poughkeepsie around it) is a city in the U.S. state of New York. It is the county seat of Dutchess County, with a 2020 census population of 31,577. Poughkeeps ...

and all the equipment was moved to Dearborn. Some of his Swedish employees that worked in Poughkeepsie were also employed by Ford. At the age of 72, he decided to retire and went back to Sweden. During his life he had crossed the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

22 times and spent a lot of time in America. He received a number of awards and honors, including the large gold medal of the

Royal Swedish Academy of Engineering Sciences The Royal Swedish Academy of Engineering Sciences or ''Kungliga Ingenjörsvetenskapsakademien'' (IVA), founded on 24 October 1919 by King Gustaf V, is one of the royal academies in Sweden. The academy is an independent organisation, which prom ...

posthumously Posthumous may refer to: * Posthumous award - an award, prize or medal granted after the recipient's death * Posthumous publication Posthumous publication refers to material that is published after the author's death. This can be because the auth ...

in 1943, shortly after his death.

Johansson and the inch

In the 1910s, the U.S. and U.K. definitions of the

inch Measuring tape with inches The inch (symbol: in or ″) is a unit of length in the British imperial and the United States customary systems of measurement. It is equal to yard or of a foot. Derived from the Roman uncia ("twelfth ...

differed, with the U.S. inch being defined as 25.4000508mm (with a reference temperature of ) and the U.K. inch at 25.399977mm (with a reference temperature of ). When he started manufacturing gauge blocks in inch sizes in 1912, Johnanson's compromise was to manufacture gauge blocks with a nominal size of 25.4mm, with a reference temperature of 20 degrees Celsius, accurate to within a few parts per million of both official definitions. Because Johannson's blocks were so popular, his blocks became the ''de facto'' standard for manufacturers in both countries, leading industry associations to adopt 25.4 mm as the standard "industrial inch" in both the U.K. (1930) and the U.S. (1933). When the English-speaking nations jointly signed the International Yard and Pound Agreement of 1959, the inch was fixed at 25.4 mm worldwide, effectively endorsing what had already become common practice.

Family

He was married to Margareta Andersson in 1896. They had four children: Elsa, Signe, Edvard, and Gertrud.

References

Bibliography

* . *

External links

Starrett page "Wringability and Gage Blocks" by Dave Friedel, General Manager of Starrett's Webber Gage Division
* {{DEFAULTSORT:Johansson, Carl Edvard 1864 births 1943 deaths 20th-century Swedish inventors 20th-century Swedish engineers Members of the Royal Swedish Academy of Engineering Sciences