A jaw crusher consists of two plates, with one oscillating back and forth against the other at a fixed angle (figure 4.4(a)) and it is the most widely used in primary crushing stages (behera et al., ). the jaw crusher can withstand large and hard-to-break pieces of reinforced concrete, which would probably cause the other crushing machines.An impact crusher (also called a hammer crusher) is quite versatile. it can be used as a primary, secondary, or tertiary crusher. impact plates and beaters – or hammers – are used to break down the material. the material is fed through the upper part of the crusher then hit by hammers. next, the pieces are thrown toward the.