Pin Mills


Grind friable materials, reduce flakes and de-lump agglomerates into narrow particle size ranges without the use of screens

A simple, inexpensive means of grinding, sizing, de-agglomerating and/or homogenizing. Ideal for a broad range of food, chemical, pharmaceutical, nutraceutical, mineral and agricultural products — including pulverizing of insects, eggs and larvae in flour applications — in tight size ranges from coarse to 400 mesh.

MUNSON's Pin Mill, or "Centrifugal Impact Mill," reduces bulk materials into narrow particle size ranges without the need for screens, hammers, knives or rolls.

Instead, it relies on material impacting hundreds of pins thousands of times as it travels from the center to the periphery of the milling chamber.

The chamber consists of an outer stationary (stator) disc containing circular rows of pins that alternate with concentric rows of pins on the inner rotating (runner) disc.

As metered material is gravity fed through the centrally located inlet of the stator disc, centrifugal force created by the high speed runner disc accelerates material causing particles to alternately impact the stationary pins and rotating pins before reaching the outlet.

To vary the tight range of particle sizes desired, the operator simply adjusts the speed at which the inner disc rotates, from several hundred to more than 5000 RPM depending on mill diameter. This extreme flexibility enables a MUNSON? Pin Mill, with no modifications, to grind friable materials into tight size ranges from coarse particles down to powders of 400 mesh, and to de-lump agglomerated material.


• Grinds friable materials to narrow size ranges; de-agglomerates lumpy materials
• Simple design — only one moving part contacting material
• Air-swept principle of operation keeps material cool
• Easy to clean and sanitize
• Five rows of intermeshing impact pins
• Safety interlocked access door/stator disc hinges open for unrestricted access to all internal material contact surfaces
• Vertical orientation of mill housing offers easier cleaning and sanitizing than horizontal designs
• Precision machined housing and discs
• Easy-flow inlet elbow
• Design efficiency produces high throughput rates per horsepower/kilowatt
• 5 to 125 hp (4 to 93 kw) inverter-capable motors
• Multiple V-Belt and sheave drive arrangements. Direct drive on CIM-18 only.