此迴流系統的設計經由前後兩端循環路徑，配合螺帽上貫穿孔作為鋼珠迴流，使螺帽上所有珠槽都佈滿有效鋼珠因此在相同的螺帽長度下，端塞螺帽會比外循環螺帽具較高的動負荷。
The back system is designed by the front and rear ends of cycle paths, with the nut on the through-hole as the ball back, so that all nuts are covered with bead groove ball so effectively in the same length under the nut, end plugs nuts than the outer cycle nut with higher dynamic loads.

端蓋型滾珠螺桿系列

FSKC端蓋型