A guide wire provided with a core wire (4) having a proximal-end large-diameter section (20) and distal-end small-diameter sections (22, 24, 26) and with a coil spring (12) mounted along the axial direction onto the outer periphery of the distal-end small-diameter sections (22, 24, 26) of the core wire (4), the core wire (4) comprising a wire material for which the amount of processing-induced martensite is 20-60 vol% obtained by subjecting a wire material of austenitic stainless steel to wire-drawing and straightening processing, and the warp angle of a leading-end portion imparted by winding being less than 5 DEG when a tensile load of 150 gf is applied over ten seconds in a state where the distal-end small-diameter sections of the core wire (4) onto which the coil spring (12) has been mounted have been wound once along the outer periphery of a rod 20 mm in diameter. This guide wire has even more excellent torque transmission performance than a conventionally known guide wire provided with a core wire made of stainless steel, is less susceptible to permanent deformation even when bent within a blood vessel, and has excellent shape retention performance.本發明要提供:一種醫療用導引線,其與以往習知的具有不鏽鋼芯線的導引線相較,具有更優異的轉矩傳遞性,即使在血管內將其彎折時,也不易產生永久變形之形狀保持性優異的導引線。本發明的醫療用導引線,係具備:芯線(4)與線圈彈簧(12)而構成的,芯線(4)具有近位端側大徑部(20)與遠位端側小徑部(22,24,26);線圈彈簧(12)是沿著軸方向裝設在芯線(4)的遠位端側小徑部(22,24,26)的外周;芯線(4)是由:對於沃斯田鐵系不鏽鋼線材實施了伸線(抽製鋼線)加工以及矯直加工而獲得的加工誘發的麻田散鐵量佔20~60體積%的線材所構成,在將已裝設了線圈彈簧(12)之芯線(4)的遠位端側小徑部沿著直徑為20mm的軸桿的外周捲繞1次的狀態下,施加了10秒鐘的150gf的拉伸負載之後,因捲繞而導致的前端部分的反翹角度未達5°。C‧‧‧結晶粒的範圍
