At FRANTZ Manufacturing Company, Sterling
® Steel Ball Division, we take our steel ball product Quality seriously.
We manufacture steel balls from raw material to finished product.
We control the entire process to ensure a quality product. Our steel balls are made to rigid automotive industry standards. Our Quality Management System, established in 1998, is registered to IATF 16949:2016. Click here for certificate. We have manufactured steel balls since 1947 and understand the properties that make for a quality ball product.
We have a strong product inspection process.
In addition to visual inspection of finished product, we employ roller size sorting techniques and eddy current technology to verify that your product meets expectations.
We have a sophisticated product testing laboratory.
Our laboratory examines case depth, hardness, and other metallurgical qualities that our products, balls or bearings, must meet. We sample our steel ball production runs and put the sample through a rigorous testing scheme to assure ourselves that the process is producing products that meet our own high quality standards.
Examples of Equipment in our Quality & Testing Department
Hot/Cold Epoxy Press Mount
Balls are formed in a hot/cold press epoxy powder.
Precision Wet Abrasive Cut-Off Machine

The finished mount is then cut in half with a precision cut-off machine.

The grinder and polisher is used to create a mirror-like surface on the flat surface
of the mounted and sectioned ball so that it can be examined with the metallograph.
This machine is used to make a precision indentation in a highly-polished, flat, metal surface, and then measure that indentation. The size of the indentation is directly related to the hardness of the metal at the location of the indentation. By making a series of indentations from ball surface to core, numerical values can be assigned to surface hardness, core hardness and effective case depth.
Metallograph (reflected light microscope)
The metallograph is used to examine and evaluate the internal microstructure of the ball.
Rockwell Surface Hardness Tester
This machine is used to indent the surface of a ball to check surface hardness to ABMA Standards.
Used to test fracture grain to validate proper case after heat treating.
The diameter of the balls is measured with precision gages in custom fixtures designed specifically for balls so that desired accuracy is achieved.
Surface Roughness Tester - Profilometer
The shiny surface of the balls is actually composed of tiny scratches. The instrument measures those scratches to conform to roughness standards ISO-1997 and ANSI.
This gauge is used to measure the Total Indicated Runout, or "concentricity" of bearings
and drilled ball products.
FRANTZ Sterling® Steel Ball Quality. Simply better.