WRITING INSTRUMENT

To provide a writing instrument capable of easily attaching the tail plug to the barrel while providing the tail plug with a guide for aligning the positions of the axial circumference and axial diameter with respect to the barrel.SOLUTION: The writing instrument comprises a barrel 5 and a tail plug 6 mounted on the rear end of the barrel 5. The tail plug 6 includes a flange 6d that abuts on the rear end of the barrel 5, a locking portion 6g that is locked on a locked portion 2d provided on the inner wall of the barrel 5, a guide portion formed to protrude outward in the outer peripheral portion, and a notch 6f formed in the outer peripheral portion to penetrate inside and outside and extending in the axial direction. The guide portion has a first guide portion 6h extending in the axial direction and a second guide portion 6i extending in the axial circumferential direction. The outer surface of the first guide portion 6h is provided with a first groove portion 6j extending in the axial circumferential direction, and the outer peripheral surface of the second guide portion 6i is provided with a second groove portion 6k extending in the axial circumferential direction. The first groove portion 6j and the second groove portion 6k are formed in communication with each other, and the guide portion of the tail plug 6 is axially divided by the first groove portion 6j and the second groove portion 6k.SELECTED DRAWING: Figure 2 【課題】尾栓に、軸筒に対する軸周方向及び軸径方向の位置を合わせる為のガイドを設けると共に、軸筒に対して尾栓を容易に装着可能な筆記具を提供すること。【解決手段】軸筒５と該軸筒５の後端部に装着された尾栓６とを有し、尾栓６は、軸筒５の後端部に当接する鍔部６ｄと、軸筒５の内壁に設けた被係止部２ｄに係止する係止部６ｇと、外周部に外方へ向って突出するよう形成されたガイド部と、外周部に内外を貫通するように形成され軸方向に延びる切欠部６ｆと、を具備し、ガイド部は、軸方向に延びる第一ガイド部６ｈと、軸周方向に延びる第二ガイド部６ｉと、を有し、第一ガイド部６ｈの外側面に、軸周方向に延びる第一溝部６ｊを備えると共に、第ニガイド部６ｉの外周面に、軸周方向に延びる第二溝部６ｋを備え、第一溝部６ｊと第ニ溝部６ｋとが連通するよう形成され、尾栓６のガイド部を、第一溝部６ｊ及び第ニ溝部６ｋにより軸方向に分断して形成する。【選択図】図２