A cutting unit for agricultural machines, including a rotor carrying on a base body spaced apart tine arrangements with circumferential phase shifts between adjacent tine arrangements. Each tine arrangement includes at least one tine with a base secured to the rotor base body and an outwardly protruding triangular tine tip forming a conveying flank leading in the rotor rotation direction and extending from the tine end to a transition into the base. A cutting unit bottom forms a lower boundary of a conveying channel. Cutting blades protrude from the cutting unit bottom through the conveying channel besides moving paths of the tine tips. Scrapers are placed in a conveying direction through the conveying channel behind the rotor. A compression surface provided at the base of the tine ahead of the conveying flank in the rotor rotation direction gradually ascends at least substantially up to the transition into the conveying flank.