Ballizing

Ballizing is a cold forming process used to size and finish holes. It involves forcing a hardened, oversized ball through a pre-formed hole. The ball's diameter is typically between 0.001 and 0.010 inches larger than the nominal hole size. As the ball is pushed through, it plastically deforms the material of the hole, expanding it to a precise and uniform diameter. This process improves the surface finish, increases hardness, and can create a burnished effect.

Ballizing is effective for creating tight tolerances and good surface quality in various materials, including soft metals, plastics, and composites. It is a non-cutting method, meaning it produces no chips and minimal waste. The process is generally fast and can be automated, making it suitable for high-volume production. It is often used for sizing bearing housings, hydraulic components, and other precision parts where accurate hole dimensions are critical. The ballizing tool, which holds the ball, is typically made of high-speed steel or carbide for durability.