STR Industries

Steel balls are spherical components used as rolling mechanisms in rotary motion components such as bearings, tooling, wheels, but there are other use for steel balls such as grinding or burnishing media, toys and more. There are many sizes and gauges used in a variety of applications.

Selecting the Right Steel Ball

When sourcing steel balls, consider your application and the function you need the ball to perform. Various options are available when creating steel balls and bearing balls, so you will need to consider the size and materials.

• Steel balls are available in standard and metric sizes, so determine which is most appropriate for your purpose. Standard-sized steel balls are typically less expensive and normally available for immediate delivery. However, STR Industries will design custom sizes upon request.
• Material choice dictates the physical characteristics of the steel ball, such as hardness, magnetic properties, and oxidation resistance. Steel balls are available in low carbon (1015, 1018), high carbon (1065,1085), chrome (52100), and stainless steel (302, 304, 316, 420, and 440). The intended application will play a significant role in determining the appropriate material choice.

How Steel Balls are Made

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Our engineers can provide guidance in selecting the right type of steel balls for your application, including size, materials, and quantities.
Stainless steel and other metal balls are manufactured using the following processes:

• Forging aka cold heading. Rough ball shapes are forged from bar stock material.
• Deflashing. Rough machining or soft grinding removes the forge flashing.
• Heat treatment. Balls are heat treated based on technical specifications in a controlled process.
• Finishing. Stainless steel balls skip this step. Other steel balls may be hardened using heat treatments, quenching, or other tempering methods.
• Hard Grinding. The steel balls are ground to remove nicks and imperfections.
• Lapping. A controlled mechanical sanding/polishing process brings the balls into the intended design, grade dimensions, and spherical accuracy within 1/1,000,000 of an inch.
• Inspection & Packaging. Lubricant or rust-preventive is applied as a final step before the steel balls are inspected and packaged.

Applications for Steel Balls

Steel balls have hundreds of potential uses. Some of the most common applications include:

• Automotive
• Bearings (most common)
• Casters
• Ink/chemicals as grinding media
• Military
• Paint
• Pharmaceuticals
• Rollers
• Sliders
• Sports Equipment
• Toys

 

 

Carbon Steel Ball

Material Available

• Low Carbon: AISI 1008~ AISI 1018
• Medium Carbon: AISI 1045
• High Carbon: AISI 1065~ AISI 1085

AISI NumberC %Si %Mn %Mo %P % S % Hardness AISI 1008 0.10 Max0.30 Max0.50 Max0.0120.07 Max 0.06 Max Case Hardened
HRC 55Min AISI 10150.13~0.180.10~0.300.30~0.600.020.04maxCase Hardened
HRC 55~61 AISI 10450.43~0.500.10~0.30 0.60~0.900.0250.04 Max0.05 MaxThrough Hardened
HRC 60 Min AISI 10860.83~0.880.10~0.30 0.30~0.700.040.04 Max0.04 MaxThrough Hardened
HRC 60 Min

Chemical Composition

Grade

3 ~ 1000

Size

1.0mm~ 2″

Application

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

 

 

Chrome Steel Ball

C %Si %Mn %Cr %Cu %S %P % 0.90~1.05 0.15~0.35 0.25~0.45 1.35~1.65 0.3 Max 0.03 Max 0.03 Max

Chemical Composition

Density

7.84 g/cm3

Hardness

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

Size

0.5mm~5″

Application

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

 

 

Stainless Steel Ball

Material Available

• AISI 302~AISI 316
• AISI 420~AISI 440C

AISI
NumberC %Si %Mn %Cr %Ni %Mo %P %S %Character AISI 3020.15 Max1.00 Max 2.00 Max17.0~ 19.08.0~ 10.5 0.045 Max0.03 MaxSlightly
magnetic
Austenitic AISI 3040.07 Max1.00 Max2.00 Max17.0~ 19.08.50~ 10.50.045 Max0.03 MaxSlightly
magnetic
Austenitic AISI 3160.07 Max1.00 Max2.00 Max16.5~ 18.5 10.5~ 13.52000~ 2.500.045 Max0.03 MaxNonmagnetic
Austenitic
Excellent corrosion
resistance AISI 420J0.17~ 0.251.00 Max1.00 Max 12.0~ 14.00.045 Max 0.03 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 Max 16.0~ 18.00.40~ 0.800.04 Max0.02 MaxFair corrosion
resistance
Hardenable HRC
58 Min

Chemical Composition

Grade

10~1000

Size

0.5mm~2″

Application

Dispenser valve ball, stainless steel bearing, chemical related application

    Steel Balls Applications  

In Ball Bearings
Grade 20, hardened chrome steel balls are applicable.
Manufactured in high carbon high chrome steel, also called bearing steel (AISI-52100 / EN-31)
Ball Diameter Tolerance: 0.000020 inch or 0.0005 mm or 0.50 microns.
Basic Diameter Tolerance: ± 0.0001" or ± 0.0025 mm or ± 2.50 microns.

 

In Bicycles
Grade 200 or 500 are suitable.
Manufactured in hardened high carbon high chrome steel (AISI-52100 / EN-31 / EN-9 / M.S.)
Generally used diameter (in inches) are 1/8", 1/4", 3/16", 5/32".

 

In Automotive Sub-assemblies
Generally stainless steel balls, AISI 304 or 316; Grade 100 are used.

 

In Valves
Material AISI 304 and AISI 316 is used.
Grade 200, Basic Diameter Tolerance ± 25 microns.
Sizes 6 mm to 12.7 mm and 1/4" to 1/2" diameters.

 

As Agitators
In the plating bath for plating zinc and lead
In the plating baths, chrome steel balls of 1, 1.5 and 2 mm diameters are used. High tolerance is not required and hence, grade 1000 polished ball is generally suitable. At times, stainless balls of 304 steel are also used.

In paint spray cans
Here balls of 3/8" or 10 mm diameters, G-1000 are used. The steel balls stir up the paint and mix it thoroughly.

In personal care products like nail polish
Because of non-usage, the fluid coagulates and the bottle is shaken to homogenize the fluid and make it free flowing. The bottle contains a steel ball which is used as an agitator ball to help in achieving the above when the bottle is shaken. Because of the fluid, the steel balls can be prone to corrosion, hence AISI 316 stainless balls are preferred. 3 and 5 mm sizes (1/8" and 3/16" diameters) are generally used. Grade -1000 is suitable for this application.

As valve for spray pumps and dispensers
Stainless steel AISI-316 balls are used in spray pumps as a one way valve. SS-316 (Chromium 16-18%, Nickel 10-12%) has good corrosion resistance which is essential for personal care products and cosmetics. At times, in detergent pumps, AISI-304 stainless steel ball is used.

Tolerance of the steel ball ranges from G-100 to G-500 depending upon the quality and performance specifications of the overall product.

2, 3, 4 and 5 mm or 3/32", 1/8", 5/32" and 3/16 inch diameter balls are generally used.

Micro spray pumps in which these stainless steel balls are used include deodorant spray pumps, eau-de-cologne spray pumps, viscous liquid spray pumps (for liquid soap and detergents), gel pumps, toothpaste pumps, pocket spray pumps, spray pumps for metal container (without gas pressure) and insecticide spray pumps.

In Decorative Use
Designer Furniture and Interiors
Artificial & Body Jewellery
Spectacle Frames
Handicrafts
Watches   Other Applications
Computer Hard Disc
Computer Mouse
Household Appliances
Gas Regulator
Conveyors Roller Skates
Drawer Slides
Door Locks
Ball Pen
Toys