Top: Bolt flat top Bottom: Weld cone bottom Agitator: 316SS worm type Shaft thickness: 3/4" (19mm) Worm diameter: 4 1/4" (107mm) varispeed gearbox. W/spare agit. Openings: top 1-12" (304mm) x 10 1/2" (266mm) feed chute; btm 1-2" (50mm) discharge.