SPI Supplies Brand Agate Ball Mill Grinder Balls, 12 mm Diameter, Pack of 25 Balls

Introduction:
There is a class of grinding apparatus called "ball mills", and are manufactured by firms such as Spex Certiprep, Glen Mills, Inc., Retsch and other fine ball mill manufacturers. The concept of operation is easy enough to understand: Balls of a particular hardness are tumbled in a closed container to erode the size of the material being ground. The balls are available in a variety of different diameters to produce different effects on different materials. 

Why agate?
Agate, a quartz mineral, is a very attractive choice in material because of its extreme hardness (Mohs hardness of ~7) The only grinding balls that have a higher hardness value are those made from zirconia (Mohs hardness of ~ 10). Only diamond is harder than zirconia. We have found agate to be quite acceptable for most of the most demanding of applications where freedom from grinding media contamination is crucial. 

Where can the SPI Supplies brand grinding balls be used?
They can be used literally in any ball mill designed for using "ball" type media such as Spex Certiprep, Glen Mills, Inc., Retsch, and other fine ball mill manufacturers. 

Precision of the statement of diameter:
± 0.1 mm . Note that this is a tighter specification than some competitors. One needs diameter uniformity for many applications and we feature only a tight size distribution of the ball product. Some would call this "Grade A".