A roller-grinder is a specific type of mill used to grind a wide range of products, while an hd roller-grinder is a specific type of mill used to grind a high capacity of a wide range of products. roller-grinders have the ability to break down products to a consistent particle size without over-processing the material or creating too many.A roller-mill is a specific type of commercial mill designed to crack, crimp or crush the product being run through it. ... the range of moisture levels that this type of mill is compatible with is from very dry all the way to high moisture. roller mill features: strong construction. ... 300 / : 300 / : 300 / - 250 / - 250 / - 150 / - 1.