tooriku plastse deformatsioonikoldega kontakteeruva valtsi välispinna kaar valtsimisprotsessi stabiilses režiimis; kontaktkaar on haardekaarest väiksem (vt kontaktnurk; vrd haardekaar), the length of the arc of contact between the rolls and the rolled workpiece; this arc in operating regime of rolling is less than arc of bite (see: angle of contact; compare: arc of bite)