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The first product Prater (formerly Prater Pulverizer) developed was a hammer mill, also known as hammer forges or hammer works. Since that time, our company has sold thousands of hammer mills to customers in various industries. For over 90 years, we have relied on advanced technology to properly engineer our mills for new applications. Prater continues to provide solutions for some of the most demanding processing challenges with our innovative designs, industry expertise, and advancements that provide a shorter wait for your business’ return on investment. Our hammer mills are commonly used for many different particle reduction applications, including those that require high capacities, extreme power efficiency, and uniform particle size.

With a Prater hammer mill, you can increase the mill’s throughput capacity without having to increase its power requirements. Companies both large and small rely on Prater for efficient milling solutions and proven expertise.

Prater hammer mills are the premier choice for applications requiring high capacities, operational efficiency, and uniform particle size distributions. All five Prater Full-Screen hammer mills are equipped with our proprietary Full-Screen design that enhances end-product quality while simultaneously extending unit lifespan. Major applications include:

  • Conditioning of agglomerated blends
  • Granulating of almost any material
  • Recycling operations
  • Reworking of off-spec products

These hammer mills are ideal for a variety of products, including:

Important features of Prater Full-Screen Hammer Mills include:

  • Durable, heavy-duty fabrication designed for superior operation and long lifespan
  • 100% of screen utilized for maximum efficiency
  • A variety of hammer sizes, patterns, and screen openings available to tailor parameters for each application
  • Balanced HP to screen area for maximum power efficiency
  • Symmetrical, precision balanced, and reversible rotors
  • Durable pillow-block bearings enhance unit lifespan
  • Rigid-frame screen mounting for uniform hammer-to-screen clearance
  • Unique frame track designed for easy screen removal and interchange without tools
  • Large access doors make cleaning and maintenance simple and quick
  • Stainless steel and sanitary design available
  • Optional wear liners and wear-resistant hammers for abrasive products

The Prater Full-Screen Hammermill utilizes a specially shaped grinding chamber designed with distinct grind-and-release zones. Coarse raw product is fed into the chamber, using a rotary feeder or screw, by way of a product inlet at the top of the unit. High-speed hammers impact coarse material against stationary cutting plates fixed to the top of the pre-grind chamber. Impact with the cutting plates decreases the velocity of the material and guides it into the hammer path for maximum impact speed differential. Screen-to-hammer clearance is minimized at the 3 o’clock and 9 o’clock positions to amplify impact. As material moves toward the bottom of the chamber, hammer-to-screen clearance increases toward the 6 o’clock position to help with deceleration and egress of fully conditioned particles through the sizing screen. An adjustable diverter system prevents unfinished product from re-entering the inlet and product feed stream. Finished product is discharged via a hopper below the mill where a mechanical conveyor or pneumatic system can be utilized to remove the ground material.  Prater provides a full inventory of hammers, screens, and other grinding elements that are available to satisfy almost any grinding application.

The accompanying schematic illustrates how Prater Full-Screen Hammer Mills, which can be operated as a stand alone, gravity application or pneumatic circuit, can be integrated into your total operating system:

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.

Choose Metric

Hammermill Particle Size
  • 50,000 - 10,000
  • 50.00 - 10.000
  • 2.215 - 0.443
  • N/A
  • 2,000 - 250
  • 2.00 - 0.25
  • 0.0787 - 0.0098
  • 10 - 60
  • 1000 - 73
  • 1 - 0.073
  • 0.0394 - 0.0029
  • 18 - 200
  • 150 - 73
  • 0.15 - 0.073
  • 0.0059 - 0.0029
  • 100 - 200
  • 150 - 30
  • 0.150 - 0.030
  • 0.0038 - 0.0012
  • 150 - 400

Microns Millimeters Decimal (Inches) Mesh


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