Twine wrapping apparatus for a round baler having a bale forming chamber with a generally transverse crop infeed opening. The apparatus is mounted forward of the opening and includes a twine arm for dispensing twine into the chamber to wrap cylindrical packages of crop material formed therein. Coupling means provide for swinging movement of the arm through a predetermined path during at least a portion of which the arm dispenses twine in the vicinity of the opening. The twine arm includes a clamp having one member affixed to the outer end of the twine arm and a second member that is moveable relative to the first member and is urged thereagainst by a spring assembly to provide a clamping force for holding the twine. The spring assembly includes a spring maintained in compression.