A conical crusher having a rigidly supported outer frustoconically shaped crushing member and an inner conical crushing member supported on a wobble mechanism which is in turn supported by air bellows. The air pressure in the air bellows is regulated to adjust the spacing between the inner and outer crushing members, and therefore the particle size of the crushed material. The inner and outer crushing members are readily replaceable. The inner crushing member serves as a single piece crushing head/mantle attachment.