The spool shaft comprises a shaft portion, two annular first annular portions arranged on opposite ends of the shaft portion, and an annular second larger diameter portion arranged on the end of the shaft portion positioned remote from a center of the spool. Each of the first annular portions and the second larger diameter portion have an outer diameter that is larger than the outer diameter of the shaft portion. The second larger diameter portion is arranged on an outward side of the first annular portion in the axial direction so as to create a space therein between the first annular portion and second larger diameter portion.對於雙軸承捲線器的捲筒,減少捲筒軸的外周面及內輪接觸的接觸面積,並且捲筒在高速旋轉時防止捲筒軸的擺動。捲筒軸(16),是具備:軸部(16c)、及軸部(16c)的兩端外周部的一部分是各別比軸部(16c)大徑的方式形成的環狀的第1大徑部(16d)、及與第1大徑部(16d)隔有間隔且配置於比第1大徑部(16d)更外方且遠離捲筒(4)的中心的側的軸部(16c)的一端外周部的一部分是比軸部(16c)大徑的方式形成的環狀的第2大徑部(16e)。7a...轂部7b...公螺紋部7d...裝設凹部7e...裝設溝部16...捲筒軸16b...第2端部16c...軸部16d...第1大徑部16e...第2大徑部16i...第4軸部20...拋竿控制機構30b...第2軸承30c...外輪30d...內輪30e...鋼球40...摩擦托板41...帽構件42...彈簧構件
