There are dozens of mill designs and configurations available today. Many are capable of handling materials such as grain, biochar, coffee, or minerals with acceptable results.
Where they begin to separate is in efficiency. Grind consistency, energy consumption per ton, operating cost, and downtime can vary dramatically depending on the design.
Understanding the core types of mills makes it easier to evaluate which machine aligns best with your material and production priorities. This guide walks through the most common industrial mills, explains how they reduce material, and places each one along the particle size spectrum so the differences are easy to see.
Comparing the Most Common Types of Milling Machines
| Mill Type | Typical Feed Size | Typical Product Size | Throughput Character | Energy Consumption (kWh/ton relative) | Best Applications |
|---|---|---|---|---|---|
| Jaw / Primary Crusher | 3 – 10 in | ¾ – 4 in | Very High | Very Low | Mining, minerals, large lump reduction |
| Roll Crusher | ½ – 4 in | 4 – 20 mesh | High | Low | Coal, salt, minerals |
| Hammer Mill | ¼ – 2 in | 10 – 325 mesh | High | Medium – High | Feed, grain, biomass, chemicals |
| Roller Mill | ¼ – 1 in | 12 – 150 mesh | High | Low | Grains, soft minerals, and other friable materials |
| Cone Mill (Comil) | ⅛ – in agglomerates | 6 – 80 mesh | Medium – High | Low – Medium | Food, pharma, powder conditioning |
| Pin Mill | ⅛ – ½ in | 50 – 400 mesh | Medium | Medium | Sugar, spices, chemicals |
| Attrition / Disc Mill | ⅛ – ½ in | 80 – 500 mesh | Medium | Medium – High | Fillers, minerals |
| Jet Mill | 30 – 325 mesh feed | <10 µm equivalent | Low – Medium | Very High | Pigments, pharma, specialty chemicals |
| Ball Mill | <½ in | 100 – 325 mesh | Medium | High | Minerals, cement |
| Agitated Media Mill | <80 mesh feed | Sub – 10 µm | Medium | High – Very High | Ultrafine minerals, pigments |
Equipment Types
Jaw / Primary Crusher
A jaw crusher is a primary size reduction machine that uses compressive force between two plates (jaws) to break large material into smaller pieces. One jaw is stationary while the other moves in a reciprocating motion. Jaw crushers are typically the first stage of size reduction when large rocks, ore, or other bulk solids must be reduced before further processing.
Roll Crusher
A roll crusher uses two counter-rotating cylindrical rolls to compress and fracture material as it passes between them. The gap between the rolls determines the final particle size. Roll crushers are commonly used when a controlled top size with minimal fines is desired.
Hammer Mill
A hammer mill reduces particle size using high-speed rotating hammers that impact and shatter the material against breaker plates or a screen. The final particle size is typically controlled by the screen opening. Hammer mills are widely used because they can handle a broad range of materials and feed sizes.
Roller Mill
A roller mill reduces material size through compressive grinding between rotating cylindrical rolls. Material is drawn into the roll gap and fractured by pressure rather than impact. Roller mills are valued for producing uniform particle size distributions with fewer fines and lower energy consumption compared to impact mills.
Cone Mill (Comil)
A cone mill is designed primarily for powder conditioning and deagglomeration rather than aggressive grinding. Material is fed into a rotating impeller that pushes particles through a conical screen. Cone mills are commonly used when gentle particle size reduction and minimal heat generation are required.
Pin Mill
A pin mill uses two rotating discs equipped with intermeshing pins to impact and shear material. One disc may rotate while the other is stationary or counter-rotating. Pin mills are capable of producing fine powders with relatively narrow particle size distributions.
Attrition / Disc Mill
An attrition or disc mill reduces particle size through shear and abrasion between two closely spaced grinding surfaces or discs. One disc typically rotates while the other remains stationary. This grinding mechanism is effective for producing fine powders from relatively brittle materials.
Jet Mill
A jet mill uses high-velocity compressed gas streams to accelerate particles and cause them to collide with each other. Size reduction occurs through particle-to-particle impact rather than mechanical grinding surfaces, which minimizes contamination and heat generation. Jet mills are commonly used for ultrafine grinding applications.
Ball Mill
A ball mill is a rotating cylindrical vessel partially filled with grinding media such as steel or ceramic balls. As the mill rotates, the media tumble and grind the material through impact and abrasion. Ball mills are widely used in mineral processing and other industries requiring fine particle size reduction.
Agitated Media Mill
An agitated media mill (sometimes called a stirred media mill) uses small grinding media that are mechanically agitated by a rotating shaft or discs. The intense movement of media produces very high grinding efficiency for fine and ultrafine materials. These mills are commonly used when very small particle sizes are required.
See How RMS Roller Mills Compare in Real-World Applications
If roller-based reduction looks like the right fit for your material, it’s worth seeing how RMS approaches the design.
RMS builds advanced roll crushers and roller mills that give operators direct control over particle size while supporting consistent throughput across demanding applications. Our systems are engineered for durability, repeatable performance, and efficient operation.
If you’re reviewing industrial mills for an upcoming project or considering an upgrade, the RMS team can evaluate your material and target specifications to help determine the right configuration.
Looking to see if a roll crusher or a roller mill can live up to the hype? Explore RMS roller mills or schedule a free demo in our test lab with your material.
