Precision Ball Manufacturing


STR Industries is a manufacturer of high-quality precision balls suitable for use in a wide range of applications, including art design, product manufacturing, finishing operations, and more. Equipped with over five decades of experience manufacturing steel balls, our team has the knowledge and skills to design and deliver high-precision, high-accuracy balls in a variety of shapes, sizes, and materials. Below we provide an overview of our ball manufacturing offerings, which includes:

Steel Balls

steel balls


Steel balls are commonly used as rolling mechanisms and other spherical components in products such as automotive bearings, casters, rollers, sliders, sports equipment, and toys.

When selecting a steel ball for a project, it is important to consider performance and application-specific requirements, as these factors determine what material properties (and, therefore, what materials) are required. Each steel grade offers distinct characteristics that make it suitable for different applications.



Our steel balls are available in the following grades:


Grade and Tolerance - Inches

Size Range Deviation from Spherical Range Lot Diameter Variation Allowable Ball Gage Variation Nominal Ball Diameter Tolerance Marking Increments Maximum Surface Roughness 1 in Micro inches “Ra”
.006 - 2"0.0000030.000003±0.00003-0.000010.5
.006 - 6"0.0000050.000005±0.00005-0.000010.8
.006 - 10"0.000010.000010±0.00005-0.000011.0
.006 - 10"0.0000250.000025±0.00010-0.000012.0
.006 - 10"0.000050.000050-±0.00020.000053.0
.006 - 10"0.00010.0001-±0.0005-5.0
.006 - 10"0.00020.0002-±0.001-8.0
.006 - 10"0.0010.001-±0.005--



stainless steel balls information


steel ballsStainless steel is a steel alloy consisting of approximately 89% steel and 11% chromium. It demonstrates resistance to corrosion and staining, both of which make it suitable for applications where cleanliness and corrosion resistance are critical (e.g., buildings, cutlery, and medical devices). There are two variations available: hardened and non-hardened.


  • Hardened stainless steel balls are fabricated using Martensitic processes, which increase their carbon level and make them more durable and wear-resistant. They are generally used as ball bearings in high-friction devices, such as lighters, pens, and pumps.

We offer the following types of hardened stainless steel balls:

    • AISI 420A/420B stainless steel balls
    • AISI 420C stainless steel balls
    • AISI 440C stainless steel balls
    • AISI 431 stainless steel balls
    • Lescalloy® BG42® VIM-VAR balls

hardened vs non-hardened stainless steel

  • Non-hardened stainless steel balls are manufactured with Austenitic processes, which introduce nickel and carbon into the material. While this type of steel is more workable than its hardened counterpart, it tends to be less corrosion resistant. These balls are generally used in electronic components.


We offer the following selection of non-hardened stainless steel balls:

    • AISI 204 Cu stainless steel balls
    • AISI 302/304/304L stainless steel balls
    • AISI 303 stainless steel balls
    • AISI 316/316L stainless steel balls
    • AISI 316Ti stainless steel balls
    • AISI 430/430F stainless steel balls
    • AISI 904L stainless steel balls
    • Super duplex 2507 stainless steel balls


. Bearing Steel

bearing steel balls information

Bearing steel balls are fabricated from low-alloy hardened chromium steel, which exhibits exceptional wear resistance, hardness, surface finishing, and dimensional stability. These qualities make such balls well-suited for use in a variety of industrial and commercial applications, ranging from automobile components to conveyor belts to pumps and valves.


We manufacture the following bearing steel balls:

  • AISI 52100 100Cr6 chrome steel balls
  • Low-noise AISI 52100 high-precision chrome steel balls
  • 100CrMn6 chrome steel balls
  • 100CrMo7-3 chrome steel balls
  • 100CrMnMo8 chrome steel balls



. Carbon Steel

carbon steel balls information

Carbon steel balls consist of steel with a carbon content of less than 0.093%. The presence of carbon provides a hardening effect that adds strength and durability to the material without requiring costly hardening operations. These high-strength balls are commonly used in furniture items, sliding rails, welding appliances, polishing and milling machines, and peening applications.


We offer the following carbon steel ball options:

  • AISI 1010/1015 low-carbon steel cemented balls
  • AISI 1010/1015 low soft unhardened carbon steel balls
  • AISI 1085 high-carbon steel balls


. Tool Steel

tool steel balls information

Tool steel is a carbon alloy steel that is particularly well-suited for tool fabrication due to its exceptional hardness, abrasion resistance, and ability to preserve its shape at increased temperatures. Balls made from this material are often employed as bearing components in high-temperature equipment and systems such as aircraft and rocket engines.


The tool steel balls we supply include:

  • AISI D2 tool steel balls
  • AISI M2 tool steel balls
  • AISI M50 tool steel balls
  • AISI T15 tool steel balls
  • S-2 ROCKBIT tool steel shock-resistant balls


Other Metal Alloy Balls

A metal alloy is a metal combined with one or more other metal or non-metal elements. The resulting material tends to have enhanced physical and chemical properties, including improved strength, hardness, corrosion resistance, and formability. For precision ball manufacturing, some of the most commonly employed metal alloys are:

. Aluminum

aluminum balls information

Aluminum alloy balls demonstrate excellent strength, corrosion resistance, and hard-wearing characteristics. Additionally, their surfaces can easily be treated to have a smooth finish. They are frequently used in special bearings, valves, automotive and electric safety devices, and aviation and aerospace components. When considering aluminum alloy balls for an application, it is important to keep in mind that they are vulnerable to cracking and pitting in chloride-rich environments.


We manufacture the following types of aluminum alloy balls:

  • Aluminum alloy balls Series 1XXX
  • Aluminum alloy balls Series 2XXX
  • Aluminum alloy balls Series 3XXX
  • Aluminum alloy balls Series 5XXX
  • Aluminum alloy balls Series 6XXX
  • Aluminum alloy balls Series 7XXX


. Brass-Copper-Bronze Alloy

brass copper bronze balls information

Brass, bronze, and other copper alloys are also used in precision ball manufacturing. They exhibit a variety of advantageous properties, including corrosion resistance, workability, durability, and visually appealing surface finishes.


We supply the following metal alloy balls:

  • Brass balls
  • Bronze aluminum alloy balls
  • Bronze aluminum nickel alloy balls
  • Copper balls
  • Copper beryllium alloy balls
  • Phosphor bronze alloy balls

Plastic Balls

plastic balls information

The properties of plastics make them well-suited for the fabrication of balls with low density, excellent corrosion resistance, and high durability. Depending on the type of feedstock used, the balls may also demonstrate other performance characteristics, such as resistance to damage from abrasion or high temperatures. Some common uses for plastic balls include appliances, low-load bearings, furniture sliding rails, medical and laboratory instruments, and pumps and valves.


We offer an extensive selection of plastic balls made from various high-quality feedstocks, including:

  • ABS balls
  • Acrylic (PMMA) balls
  • Composite plastic balls
  • Delrin® (POM) balls
  • Glass-filled plastic balls
  • High-density polyethylene (HDPE) balls
  • Hytrel® (TPE) balls
  • Low-density polyethylene (LDPE) balls
  • Machined rod end plastic balls
  • Nylon 6/Nylon 6.6 (PA 6/PA 6.6) balls
  • PEEK balls
  • Phenolic resin balls
  • Polycarbonate (PC) balls
  • Polyketone (PK) balls
  • Polypropylene (PP) balls
  • Polystyrene (PS) balls
  • Polyurethane (TPU) balls
  • PVC balls
  • PVDF balls
  • Teflon® (PTFE) balls
  • Torlon® balls
  • Ultra-high molecular weight (UHMW) polyethylene balls
  • Vespel® balls

Ceramic Balls

ceramic balls information

Ceramic balls are constructed from a wide range of materials, depending on the needs of the application. In addition to being extremely resistant to corrosion and wear, they require minimal lubrication to operate smoothly and efficiently and are exceptionally tolerant of acidic, alkaline, and high-temperature conditions. These characteristics make them well-suited for a number of high-performance applications, including flow valves in chemical systems, pumps, water treatment systems, and special bearings.



We fabricate the following types of ceramic balls:

Ceramic media white Beads

  • Aluminum oxide (Al2O3) balls
  • Ruby balls
  • Sapphire balls
  • Silicon carbide (SiC) balls
  • Silicon nitride (Si3N4) balls
  • Zirconium oxide (ZrO2) balls
  • Zirconia toughened alumina (ZTA) ceramic balls


Glass Balls

glass balls information

Glass balls offer corrosion resistance and electrical insulating properties. Additionally, they are available in transparent variations for use in optical devices. Typical applications include medical devices, pumps, gauges, and water treatment bearings.

Glass Specialty Balls


Our glass ball selection includes:

  • Black glass balls
  • Borosilicate glass balls
  • Quartz (SiO2) balls
  • Soda lime glass balls



Why Choose STR Industries for Your Precision Ball Manufacturing Needs?


Whether they are made from metal, plastic, glass, or ceramic, precision balls play a critical role in many industrial devices, equipment, and systems. For all of your precision balls needs, turn to the experts at STR Industries.


Over our 50 years in business, we built an extensive selection of high-quality ball products suitable for use in some of the most critical industrial and commercial applications. Our team works closely with customers to design and develop precision ball solutions tailored to meet exacting specifications. To learn more about our precision ball manufacturing capabilities, contact us today.