A breaker having a first end and a second opposed end and a plurality of breaker drums arranged side by side in a row extending between said ends, the drums being arranged with their axes of rotation parallel to one another, at least two neighboring drums adjacent to the first end being arranged to continuously rotate in the same direction to define feeder drums for feeding material toward the second end, each breaker drum having radially projecting breaker teeth which co-operate with opposed breaker teeth on the adjacent drum to grip oversized material therebetween to cause breakage thereof, to permit passage of undersized material therebetween and to move unbroken oversized material toward said second end.