What Materials Are Baseballs Made of?
Major League Baseball purchased more than 600,000 baseballs from the manufacturer Rawlings in 1998. These baseballs are all uniform in construction to ensure they are are uniform in performance. Therefore all baseballs used in professional play are made from the same materials. While these materials have changed in the past, they have been kept standard in recent years.
How Are Baseballs Made?
You might be surprised to learn that baseballs are sewn by hand. According to Rawlings employee Steve Johnson, the company tried for 10 years to invent a machine that would sew the outer casings together. Their attempts failed to replicated the precise tension produced in hand-sewn balls. Therefore seamstresses are presented with the core of a baseball surrounded by a leather cover with pre-punched holes that they must stitch with a custom-made needle.
All baseballs used by Major League Baseball consist of the same materials. An inner core is made of rubber-coated cork and then surrounded by three layers of wool yarn and a winding of cotton or polyester yarn. This core is then coated in latex adhesive or rubber cement and covered with cowhide. Stitching is then done with red cotton thread to yield 216 raised cotton stitches.
Where Are Baseballs Made?
Today China produces around 80 percent of baseballs on the world market. However, all baseballs used by the Major League Baseball are produced by the company Rawlings. Their factory is located in Costa Rica.
Today baseballs are made with cowhide but until 1974 they were made with horsehide. The changeover occurred because horsehide was becoming difficult to acquire. Rubber coated cork became the center of baseballs in 1910, replacing solid rubber. Previous experiments with cork alone had failed because the wool windings would swell after manufacture.
Evelyn Broderick has been a writer since 2004. Her work has been published by the Jewish Alliance for Women in Science. She holds a Bachelor of Science in chemistry and biology from Macaulay Honors College and is pursuing an M.D./Ph.D. in immunology at Sloan Kettering. She is also a member of the New York Academy of Sciences.