Metal Balls Information
Metal balls are rolling, spherical elements that exhibit greater strength and toughness than plastic and ceramic balls. They have a sufficient hardness for many industrial ball applications, and most products are electrically conductive. Some steel, nickel, and cobalt balls can be magnetized. Metal balls made from certain alloys can also provide corrosion resistance and refractory resistance.
How Metal Balls are Made
Metal balls are manufactured in a series of steps. First, bar stock pieces are forged into rough ball shapes or preforms. The forging flash is removed by rough machining or soft grinding. For some steel balls, hardening is achieved through a quench and tempering heat-treatment process. Nonferrous alloys and products made of austenitic stainless steel skip this quench and tempering step. Different heating treating or homogenization processes are used for certain nonferrous alloys and specific grades of stainless steel grades.
Finally, the metal balls are precision-finished through hard grinding, lapping, and polishing. The balls are then treated with and lubricant or rust-preventive, inspected, and packaged. The precision finishing step brings the balls into design or grade dimensions. Form specifications such as diameter, sphericity and surface finish are achieved by removing cuts, scratches, scuffs, and other breaks in surface continuity.
Applications for Metal Balls
The GlobalSpec SpecSearch database contains information about these and other applications for metal balls.
- Balls made from electrically-conductive metals such as brass, copper, silver, and gold are used in electrical contacts, battery safety releases, switches and microelectronic interconnects. Dielectric balls are used in electrical and electronic applications.
- Balls for valve applications include products for check valves and ball valves, as well as trunnion, segment, stem, three-way, four-way, poly or multiple way, and two-piece balls. Valve balls must have a controlled sphericity and sufficient tolerances for proper sealing against the valve seat. Typically, these metal balls have through-hole. They may also have a thread bore, slot, or stem. The through-hole provides a more uniform flow between the open and closed states.
- Lower density or hollow balls are often used in float and level sensing applications.
- S2 tool steel balls are often specified for petrochemical, oil and gas and mining applications when other types of metal balls can’t handle exposure to impact, erosive drilling and mining fluids, and abrasive minerals.
- Metal balls with suitable corrosion and density (weight) are used as agitator balls agitation or mixing applications in aerosol cans or mixers.
Other applications for metal balls include proprietary, patented or specialty applications such as drilling equipment, hardness testers, swivel balls, pinball machine balls, weights, toys, bicycle parts, foosball balls, handles, knobs, skates, drawer slides, spacers, fillers, projectiles, marine parts, door locks, and coffee makers.
Materials of Construction
They are usually made from alloy steel, carbon steel, stainless steel, tool steel, cobalt or cobalt alloys, copper or copper alloys, nickel or nickel alloys, titanium or titanium alloys, specialized ferrous alloys, or miscellaneous nonferrous metals.