How Are Major League Baseballs Made?

Although the answer to this question may seem like common knowledge, the process of making a major league baseball is actually quite fascinating.

The Raw Materials

Raw materials for Major League Baseballs come from all over the world. The cores are made of cork mixed with a rubber compound. The yarn that winds around the core is made of wool, which is traditionally stretch-resistant. The stitches are then made of cotton thread. The cover is made of cowhide leather, which is tanned and dyed.

The Core

At the very center of every baseball is a small rubber or cork-like substance called the core. MLB requires that every ball have a core made of natural rubber, but some lower-level leagues allow for cores made of synthetic rubber or a mix of the two. The core is important because it’s what the rest of the baseball is built around, and it has a big impact on how the ball performs.

The Cover

Baseballs used in Major League Baseball are hand-sewn with cowhide leather. The cover of a baseball is made up of two strips of white cowhide leather. The strips are sewn together with red thread in a figure eight pattern. Once the two strips are sewn together, they are hand-stitched onto a rubber core. The rubber core is made up of cork, black rubber, and two layers of winding.

The Winding

The process starts with the winding. A machine measuring 6 feet tall and weighing 2,000 pounds uses four bobbins of thread to wind yarn around a core of rubber cork. It takes 18 minutes to finish a ball – 10 minutes longer than it did in the early 1900s, thanks to the introduction of synthetic fibers that have made the yarn stronger and more consistent.

The Manufacturing Process

The process of making a Major League Baseball is long and detailed, and it all starts with the yarn. Raw wool is shipped to the manufacturing plant where it is dyed and spun into fine yarn. From there, the yarn is sent to the stitching room where it is cut and sewn into the shape of a baseball. Once the baseball is formed, it is hand-stitched and then sent to the inspection department.

The Core

All baseballs have a small, hard rubber or cork core at the center. This is surrounded by tightly wound string, and then by a layer of black rubber. The size and weight of the core determine the overall size and weight of the ball. For example, a regulation baseball has a core that weighs about 3 ounces and is about 2 inches in diameter.

The cores of major league baseballs are made in Costa Rica. They start as small rubber balls that are heated until they are soft enough to be cut open. The cores are then placed on a metal mandrel, or rod, that has been machined to the exact specifications of a baseball. The mandrel is placed into a lathe, or rotating machine, that cuts away anything that doesn’t look like a baseball.

Once the cores are shaped, they are covered with string. A workers sits at a winding machine and feeds string onto theMandrel. The machine winds the string tight around the core, until it is fully covered. Once the string is in place, another layer of rubber is added to hold everything in place.

The Cover

The cover of a Major League baseball is made up of two strips of white cowhide leather. The strips are placed crosswise and glued together. They are then vulcanized, or treated with heat and pressure to make them stronger and more elastic. Once the cover is complete, it is sewn together with 108 double stitches in red thread.

The Winding

Major League Baseballs are made from cowhide that is tanned and then cut into strips that are 3/8 of an inch wide and 42 inches long. These strips are then sewn together, creating a big U-shaped piece of leather. The next step is to cut out the rounded parts of the U, which will become the baseball’s cover. Once the cover is cut, it’s time to start stitching it together.

A machine called a winder takes the leather cover and stitches it together with a thread made of polyester and Kevlar (the same material used in bulletproof vests). The Kevlar makes the thread extra strong so it won’t break when the ball is hit with a bat. After the cover is stitched together, it’s time to start winding the ball.

A small piece of cork or rubber (called a pill) is placed in the center of the leather cover. The cover is then placed on a metal mandrel (a rod that gives shape to something being manufactured). Once the ball is on the mandrel, another machine called a winder starts winding yarn around the ball. The yarn is wound around the ball until there are 216 yards of it wrapped around the pill. That’s enough yarn to stretch from home plate to first base!

Quality Control

Major League Baseballs are hand-crafted in Costa Rica from the finest materials available. The process begins with a careful selection of top-quality leather. The leather is cut into panels and stitched together by hand to create the baseball’s cover. Once the cover is complete, the baseball is ready to be hand-wound with premium yarn.

The Core

One of the most important parts of a baseball is the core. The core is made up of three parts: the cork center, the rubber inner mantle, and the yarn windings. The cork center is vulcanized to the rubber inner mantle. The yarn windings are then tightly wound around the rubber inner mantle. All three parts are then covered with a cowhide leather cover.

The Cover

MLB baseballs are made with a cowhide cover that is hand-stitched over a cork and rubber core. The cowhide used to make each baseball has been tanned and treated in a process that takes close to six months. Once the cover is made, it is sent to a factory where the MLB logo, player signatures, and team logos are stamped onto the surface.

The Winding

Once the cork and rubber core have been inserted into the ball, the last step in its construction is winding. Different types of yarn are used for different parts of the baseball. The “windings” consist of a special yarn that is tightly wound around the rubber center and then another layer of yarn is wound around it. Finally, a “finish” yarn is added for appearance and to keep the other layers in place.

The amount of yarn used in each baseball is closely regulated by Major League Baseball to ensure that no team has an advantage over another. Once the baseballs have been wound, they are individually weighed to make sure they meet MLB requirements. After that, they are hand-sewn together with red thread and then inspected again to make sure they meet all MLB specifications.