Grinding Media

STR Industries manufacturing plant

Grinding Media Services

Selecting the proper media for grinding and milling operations is essential. Grinding media is used in these processes to grind or crush material to both reduce particle size and refine material. Grinding media is available in a broad variety of materials, shapes, and sizes. Which media is appropriate depends on the specifics of the intended application.
Mixing, crushing, dispersing, and purifying variable materials generally requires some type of grinding media ball or bead. Various properties influence how the work material is processed and how long the media can be used for. Many facets of grinding media can be customized, such as:

  • Material composition
  • Density
  • Bulk density
  • Hardness
  • Surface finish
  • Color

STR Industries is a professional ball manufacturer and we have been manufacturing media for 30 years. We are TS 16949(auto industry standard, higher than ISO 9001) certified. Our 200,000 square foot facilities produce more than 400 metric tons of balls per month. Our product sizes range from 0.8mm to 80mm in chrome, carbon, stainless steel, plastic and ceramics material.

Our grinding media is approved by customers not only in the ink but also pigment, paste, ferrite and food industries. We have been providing customers worldwide directly with our products saving substantial amount of money. If you are not sure what media you need, we offer free consultations to make sure you get the perfect product for your operation.

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Ceramic Media (Beads/Balls)

Next Generation Ceramic Media

Ceramic media is ideal for applications that call for highly efficient grinding with low grinding media abrasion. Applications where mixing and dispersing effects impact the final outcome of a project will benefit from the use of ceramic media.

While steel media is common for grinding in many instances, it cannot be used to manufacture bright colors. Contamination from the steel is also an issue for some product types.
Ceramic beads present a number of benefits, such as:

  • Higher density
  • Similar performance to steel
  • Reduced product contamination
  • Ideal for use with white or bright colors
  • Longer service life
  • Available in nano sizes

At STR, we offer grinding media with ceramic materials such as:

Ceramic media white Beads

Zirconium Oxide (Zirconia)

Zirconia is used in grinding media, cutting tools, jewelry, refractory materials and a variety of other applications due to beneficial physical properties such as high hardness, strength, toughness, excellent wear resistance, electrical conductivity, and low thermal conductivity.

Zirconia beads make the best use of the structural properties in specific characters of zirconia. The various classifications of zirconia include:

  • Fully-stabilized Zirconia (FSZ)
  • Partial-stabilized Zirconia (PSZ)
  • Tetragonal Zirconia polycrystal (TZP)
  • Tetragonal toughened Zirconia (TTZ)
  • Zircon (Zirconium silicate)

Featuring high density and exceptional hardness, Yttria Stabilized Zirconia Beads ZY offer higher productivity, longer mill life, and lower long-term operational costs. These 100% round and uniform beads are available in sizes ranging from 0.1–2.7 mm.

Ceria Stabilized Zirconia Beads CZ offer the highest density, optimized wear resistance, and cost effectiveness as an efficient milling media. Available sizes range from 0.3–2.7 mm, and these beads are also guaranteed to be 100% round and uniform.

Composition Density g/cm3 Bulk Density kg/l Hardness Hv Color
ZYZrO2 / Y2O3>6.02> 3.7>1350Ivory
CZZrO2 / CeO2>6.20> 3.9>1250Brown

Other Grinding Media

Composition Density Bulk Density Hardness Color
SteelSee steel info7.84.960-65 RCSilver
AluminaAl2O33.82.21600 HvWhite
ZirconZrSiO43.82.41000 HvWhite
ZYZrO2+Y2O363.61300 HvIvory
CYZrO2+CeO26.23.81200 HvBrown

Aluminum Oxide (Alumina)

Aluminum oxide is known for high strength and surface area properties, along with corrosion and heat resistance.

Material Available

  • Low Carbon: AISI 1008~ AISI 1018
  • Medium Carbon: AISI 1045
  • High Carbon: AISI 1065~ AISI 1085
AISI Number C % Si % Mn % Mo % P % S % Hardness
AISI 10080.10 Max0.30 Max0.50 Max0.0120.07 Max0.06 MaxCase Hardened HRC 55Min
AISI 10150.13~0.180.10~0.300.30~0.600.020.04maxCase Hardened HRC 55~61
AISI 10450.43~0.500.10~0.300.60~0.900.0250.04 Max0.05 MaxThrough Hardened HRC 60 Min
AISI 10860.83~0.880.10~0.300.30~0.700.040.04 Max0.04 MaxThrough Hardened HRC 60 Min

Chemical Composition


3 ~ 1000


1.0mm~ 2"


Casters, bicycle parts, light-duty bearing, hardware, toy and etc.

C % Si % Mn % Cr % Cu % S % P %
0.90~1.050.15~0.350.25~0.451.35~1.650.3 Max0.03 Max0.03 Max

Chemical Composition


7.84 g/cm3


Through hardened, HRC 60 Min. Grade
5~ 1000 grade




Bearing, Ball Screw, Linear motion guide, Auotomotive parts, Chemical, food processing.

Material Available

  • AISI 302~AISI 316
  • AISI 420~AISI 440C
AISI Number C % Si % Mn % Cr % Ni % Mo % P % S % Character
AISI 3020.15 Max1.00 Max2.00 Max17.0~ 19.08.0~ 10.50.045 Max0.03 MaxSlightly magnetic Austinitic
AISI 3040.07 Max1.00 Max2.00 Max17.0~ 19.08.50~ 10.50.045 Max0.03 MaxSlightly magnetic Austinitic
AISI 3160.07 Max1.00 Max2.00 Max16.5~ 18.510.5~ 13.52000~ 2.500.045 Max0.03 MaxNon magnetic Austinitic Excellent corrosion resistance
AISI 420J0.17~ 0.251.00 Max1.00 Max12.0~ 14.00.045 Max0.03 Maxmagnetic Hardenable HRC 48 Min fair corrosion resistance
AISI 4300.08 max1.00 Max1.00 Max15.5~ 17.50.045 Max0.03 Maxfair- good corrosion resistance
AISI 440C0.95~ 1.201.00 Max1.00 Max16.0~ 18.00.40~ 0.800.04 Max0.02 Maxfair corrosion resistance Hardenable HRC 58 Min

Chemical Composition






Dispenser valve ball, stainless steel bearing, chemical related application


Some of the industries that rely on ceramic grinding media include:

  • Inks
  • Paints
  • Advanced ceramics
  • Chemical production
  • Mining
  • Cosmetics
  • Pharmaceutical
  • Automotive
  • Water treatment

STR Industries Grinding Media Capabilities/Production Processes

In addition to ceramic media, we also offer a selection of metallic grinding media. Balls may be made of carbon steel, glass, chrome steel, or stainless steel and range from 0.8–80 mm.

Our grinding media is subjected to a variety of production and inspection processes before being sent to the customer, such as:

  • Wire – Inspections are conducted to verify dimensions, composition, and other factors.
  • Heading – Advanced controllers such as brankamp are used for precision control over the wire feeding and heading processes.
  • Flashing – Includes full parameter control and certification procedures to guarantee process quality and stability.
  • Heat treating – Relies on the use of digital controllers to regulate furnace temperature, heating time, and carbon potential. Also continuously records furnace temperatures for tracking purposes.
  • Grinding – Each step is tightly monitored and controlled.
  • Fine grinding – The final grinding step, fine grinding results in high-quality finished balls in terms of dimension, roundness, and surface finish.
  • Cleaning – The balls are washed with an automatic ultrasonic washing machine and hydrocarbon solvents. This simultaneously achieves high levels of cleanliness and imparts anti-corrosion properties.
  • Sample quality control – Ball quality is verified with the use of state-of-the-art metrology equipment.
  • 100% inspection – The product is only shipped after passing 100% inspection.

Grinding Media From STR Industries

STR Industries has been manufacturing media of various types for 30 years and we are TS 16949 certified for quality assurance. We operate more than 200,000 square feet of facility space that produces more than 400 metric tons of balls per month. Our grinding media is used by customers in sectors ranging from inks and pigments to food and beverage. Some of our customers include BASF, Akzo Nobel, Sun Chemical, and many large mill manufacturers and users.

For more information on our capabilities or available grinding media, please contact us.