Servo Polytech Coimbatore [P] Ltd. Offers Yarn Carriers with Small Step Groove. Servo Polytech Coimbatore [P] Ltd. Is an ISO 9001:2000 registered company. Yarn Carriers with Small Step Groove is provided in the bottom hole of the ring tube, which accommodates the yarn on the spindle and avoids tube jamming. Yarn Carriers with Small Step Groove has the facility of angle of pull which depends upon the ring diameter and tube diameter. The variation in circularity on the diameter of the ring tube of this yarn carrier is known as eccentricity. The wall thickness in ring tube of the yarn carrier has near spindle button which has maximum load and friction due to higher spindle speed.