What is a Baseball Made of?

What is a baseball made of

Overview of Major League standards for baseballs:

  • Must be a sphere
  • Must weigh between 5.00 and 5.25 ounces.
  • Must measure between 9.00 and 9.25 inches in circumference.

What is a baseball made of?


Let’s start at the center of the ball and work our way out. The core of a professional baseball is called “the pill.” The pill is a small round object, smaller than a golf ball, that has a rubber outer casing and a cork center.


View of a cross-sectioned “pill.”


Around the core, are several layers of tightly wrapped yarn and twine. Each layer of yarn and twine is a different thickness and texture. The multiple layers allow the ball to be pliable, and retain its round shape even after being hit repeatedly. If you attempt to unravel a baseball, it’s going to take you a while! Each ball is made up of several hundred yards (in some cases over a mile!) of yarn and twine. Manufacturers use a special machine that allows them to wrap this large amount of material so tightly around the core.


This machine wraps the yarn and twine around the pill.


Each layer of the baseball, starting with the core and ending with the twine, are covered with a thin coat of adhesive to allow the next layer to adhere. The outermost layer is a thin twine, designed to make the surface of the ball as smooth as possible. At this stage the product is now called the “center.”


The “center” of a baseball before the cover is sewn on.


The next step is to put a cover over the center. The cover of a professional baseball is made of cowhide. Some baseballs, are covered with a synthetic material, but are considered to be of a lesser quality than the genuine leather covered baseball. The leather covering consists of two figure-eight shaped cut outs that are sewn together.


The MLB rule book states that the cover must be made of two pieces of horsehide or cowhide.


Amazingly, all 108 stitches are sewn into each and every baseball by hand with needle and thread! Each ball uses 88 inches of waxed red thread.


A worker hand sews the two cover pieces onto the center of the ball.


Per Major League specifications, the balls are then placed into a press machine to press down the seams. Youth and high school baseballs seams do not get pressed down and remained raised for easier gripping by pitchers.

Finally, the balls are stamped with the official markings of Major League Baseball, including the commissioner’s signature, league marking, and brand. After 3 days of drying, the balls are all ready to go!


Check out the entire process of making a baseball in this short video below:


  1. Martin says:

    Very useful site on baseball and many people that do not watch the sport can get a feel of what it is all about. I never knew how a baseball was made and you have defined each detail on how the process is done for making this ball. I also did not realize how much yarn was used to create a baseball and that is definitely an interesting fact I could relate to a baseball fan at anytime. Good job on your website.

    1. Ryan Basham says:

      Thanks Martin, glad you enjoyed the website! Yes, it’s a fascinating process. I know I won’t ever look at a baseball the same way, now that I know the process that goes into making them.

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