Abstract: A nutcracking machine is provided which utilizes a cylindrical sizing roll and a cylindrical cracking roll. The sizing roll has a plurality of parallel circumferential grooves, the width and depth of the grooves varying in a predetermined fashion along the length of the roll. The cracking roll has a tractive surface. A spring mounting is used for adjustably and resiliently urging the sizing roll and cracking roll together to allow a predetermined lateral pressure to be exerted on the nuts passing between the rollers. The spring mounting also allows the rollers to separate momentarily to allow passage of foreign objects such as rocks. A separator is used to direct smaller nuts to one portion of the sizing roll and larger nuts to another portion of the sizing roll.