Lewis Rasmus Heim (September 19, 1874-March 29, 1964) was an American machinist, engineer and manufacturer who invented the Centerless Cylindrical Grinder and the Rod End Bearing known as the “Heim Joint”. He was also one of the pioneers of modern antifriction and spherical bearings.

Lewis Heim had an inherent ability to visualize complex mechanisms and mechanical processes that resulted in the creation of novel machines, manufacturing methods, tools and mechanical bearings. He was granted his first patent in 1896 at the age of 22 and his last patent in 1968, four years after his death at age 89. His inventions ranged from machines to manufacture hats and automate ironing of fold collars, to precision grinders and swaging devices for bearing components plus plain and antifriction bearings used in submarines, tanks, aircraft, trucks, automobiles and industrial machinery. With every invention Heim sought to improve product designs, increase production rates, and reduce costs to compete in highly competitive markets.

As the inventory of the centerless grinder, which was critical to the growth and success of the automobile and aircraft industries, Heim saw his invention revolutionize machine shop practices around the world through the high-speed production of cylindrical metal components used in the internal combustion engine, mechanical bearings and machines. His invention continues in wide use over 100 years after its conception.

As the originator of the Heim Joint, his rod end bearings were installed in nearly every American warplane produced at the end of World War II. He became internationally known as an industrialist and designer of machinery and at the time of his retirement, he was president of the Heim Company of Fairfield, Connecticut. During his long career, which spanned more than seven decades, he was granted 92 patents for his inventions, many of which are still in use today.