Prater Industries

Fine Grinding Mills

More capacity, better dust control, simple maintenance, and precise control of particle size and distribution.
Request a Quote
Fine Grinder


The “M” Series fine grinders are designed to grind dry, free-flowing material down to 400 mesh with extremely tight particle size distribution. This highly efficient machine ensures easy access to all internal areas and is perfect for heat-sensitive materials, such as resins, sugars, and powder coatings. Notable features include a final product size between 60 – 400 mesh, external bearing assembly, a dynamically balanced reversible rotor assembly, ensured tight clearances between rotors and fixed grinding elements, and a dual o-ring door seal with floating door hinge for positive sealing.

10 bar fine grinder


We are introducing a new model of fine grinders for processing materials in explosive environments such as sugar grinding from (4X to 12X) with a single pass mill. They are designed for explosion pressure shock resistance up to 10 bar (145 psi).

Key Benefits


Prater Fine Grinders (M Series Mills) are specially designed and built to grind free-flowing materials as fine as 400 mesh (37 microns) and produce uniform, narrow particle size distributions. Our highly efficient design permits ease of access to all internal components: one bolt allows for quick removal of the rotor. 

Prater Fine Grinding Mills come in six standard sizes, ranging from the 3 HP M-19 pilot-scale lab mill to the 300 HP M-101 model.

All Prater Fine Grinders are designed with standard safety features, including a trapped key door safety interlock system that prevents unintended access to internal rotating parts during operation.

Prater Fine Grinders are designed and precision-built for maximum operational efficiency and years of trouble-free operation.

Important Features

Important features of Prater Fine Grinders include:

  • Durable, welded carbon steel or stainless steel construction
  • Simple, single-stage grinding for most dry, free-flowing materials
  • Precision tolerances between rotor blade and grinding jaw or screen for uniform  size-reduction
  • Large screen-to-horsepower ratio ensures maximum capacity for each model
  • Interchangeable screen & jaw combinations for more versatility 
  • Large access door and streamlined interior for easy cleaning and maintenance
  • Grinding blades, screens and jaws designed for easy replacement with minimal tools
  • Outboard mounted spindle with high-grade labyrinth seals for maximum bearing life
  • Standard-shaft grounding brush mitigates against internal electrostatic discharge
  • Optional bearing monitoring package to complement existing predictive maintenance programs
  • Ten-Bar shock-pressure-resistant construction available
  • Sanitary construction features available

Operational Theory

Prater Fine Grinders operate on the principle of high-speed impact. Raw material is meter-fed into the center of the mill where  rotor blades impact individual particles. Material is accelerated outward, creating more impact and shear across the face of stationary jaws and screens. These stationary surfaces also deccelerate the particles, maximizing their impact speed differential as they rebound back into the rotor blade’s path. When the particles are properly sized  they are pulled through the screen apertures for transport to the next stage in the process. 

System Integration

The accompanying schematic  illustrates how Prater Fine Grinding Mills can be integrated into your operational workflow.

fine grinders system integration

We Are Here To Help

Prater stands ready to serve your needs. If your application requires a custom build, our staff will tailor a solution. Similarly, if you already own a Prater mill that requires parts, service, or an upgrade, please contact us for a free consultation.

Fine Grinder Case Studies


Not Sure Which Machine You Need?

Try our Equipment Recommendation Tool: choose a unit of measurement and desired finish size and we’ll determine which machine to use.


Ready to

Request Quote