Particle-size reduction, or comminution, is frequently necessary to prepare bulk material samples for testing. Crushing is often the primary step in size reduction of materials like mineral ores or aggregates. Jaw Crushers, Cone Crushers, and Hammer Mills use different combinations of force, impact and compression to initiate fracturing in the materials.
Pulverizing further reduces particles by friction and abrasion, and yields materials in granular or powder form for testing. These operations are sometimes secondary to crushing. Pulverizers and Disk Mills are in this category.
Milling and Grinding produce finer, more homogenous specimens by impact, pressure, and abrasion, or by cutting actions on softer materials such as plastics or plant fibers. Jar Mills, Ball Mills, Cutting Mills and Beater Mills are examples of these types of devices.