Holder for rotating cutting knives

A holder for rotating cutting knives comprising:

• a cylindrical holder including a circumferential surface and a groove provided in the circumferential surface and extending in the longitudinal direction of the cylinder, the groove defining a pair of relatively smooth side surfaces;
• a blade having a first contact surface defining a cutting edge, and an opposed, relatively smooth surface adapted to rest against one of the side surfaces of the groove;
• and
• a gib means for holding the blade within the groove of the holder, the gib means including a gib movable within the groove between a first position in which the blade may be inserted into and removed from the groove and a second position in which the blade is secured within the groove,
• the gib including a second contact face that engages the first contact face of the blade when the gib is moved to the second position, the first and second contact faces each being provided with a relatively rough area of contact defined by a plurality of side-by-side longitudinal grooves spaced from one another by longitudinal ridges sized to mate with the longitudinal grooves of the opposing contact face, wherein a substantial area of the first contact face of the blade outside the relatively rough area of contact is relatively smooth.