5mm Grinding Ball, Hardened Stainless Steel

Precision Grinding Balls for Planetary Mills

Grinding balls are fundamental components in Fritsch Planetary Mills, playing a crucial role in achieving ultra-fine particle sizes for a wide array of sample preparations. These hardened spheres are strategically placed within grinding bowls alongside your sample, where they exert powerful impact and friction forces during the milling process, effectively reducing material to the desired fineness.

Key Factors Influencing Grinding Results:

1. Ball Size: The diameter of the grinding balls directly impacts the final particle size of your sample. As a general rule:

   • Larger balls deliver higher impact energy, typically resulting in a coarser final product. They are effective for initial size reduction of larger sample pieces.
   • Smaller balls generate more contact points and increased friction, leading to finer particle distributions. They are ideal for achieving micron and sub-micron particle sizes. It is crucial to use balls of a uniform size within a single grinding jar to ensure consistent energy transfer and prevent inefficient milling.

2. Ball Quantity & Loading: Optimizing the number of grinding balls is vital for efficient milling.

   • Insufficient balls lead to prolonged grinding times and less effective size reduction.
   • Excessive balls can hinder proper movement within the bowl, reducing the efficiency of impact and friction. As a guideline, the total volume of grinding balls and sample combined should not exceed two-thirds of the grinding bowl's capacity. The remaining one-third of the bowl volume is essential for the balls to move freely and create the necessary impact energy for effective grinding. While more balls can reduce grinding times and yield finer results up to a point, the precise optimal loading is best determined through user trials for specific applications.

3. Material Hardness and Selection: To prevent contamination and ensure effective grinding, it is imperative to select grinding balls and bowls made from a material harder than your sample.

   • Hardened Stainless Steel (e.g., 5mm Grinding Ball): This material offers excellent durability and corrosion resistance, making it a versatile choice for a broad range of medium-hard to hard samples. It is a cost-effective option for general laboratory use where minimal wear and moderate hardness are sufficient.
   • Tungsten Carbide: For exceptionally hard and abrasive samples, tungsten carbide balls provide superior hardness and minimal wear.
   • Zirconium Oxide: Ideal for ceramic materials and applications where iron contamination must be avoided.
   • Agate/Silicon Nitride: Suitable for specific analytical applications requiring extremely high purity and chemical inertness. When using dissimilar materials for balls and bowls (e.g., steel balls in a ceramic bowl), there is an inherent risk of cross-contamination, which must be carefully considered, especially in sensitive analytical applications. Matching ball and bowl materials is often the best practice to minimize this risk.

This 5mm Hardened Stainless Steel Grinding Ball is designed for robust performance in Fritsch Planetary Mills, offering a balance of hardness, durability, and cost-effectiveness for a wide variety of samples.

Ordering Information: Balls with a diameter of 3mm or smaller are typically supplied in packs of 100 pieces. All other grinding ball sizes, including the 5mm hardened stainless steel, are sold individually. Classic Grinding Bowls or Premium Grinding Bowls are available for separate purchase to complete your milling setup.

Bowl Size Compatibility: This grinding ball is compatible with Fritsch Grinding Bowls of 500ml, 250ml, and 80ml capacities.