The main working part of hammer crusher is rotors with hammer. The rotors consist of main shaft, disk, pin shaft and hammers. The motor drives the rotors to rotate quickly in the crushing cavity. Raw materials enter the crusher through the feed opening and are stricken, impacted, cut and ground by the high-speed hammer to small size. There is a screening plate under the rotor, so that materials with size smaller than the screen mesh will be screened out and others are left to be further hammered and ground until reach the standard size. The size of the final product can be adjusted by changing the screening plate. The gap between the rotors and the screening plate can also be adjusted according to different requirement.