Component assembly for fishing reel

A spinning reel comprising:

• a handle;
• a reel unit rotatively supporting said handle;
• a rotor supported at a front end of said reel unit and rotatable about a spool shaft;
• a spool for winding fishing line on an outer periphery thereof, said spool being disposed at a front end of said rotor so as to be shiftable front and rear;
• and
• a drag mechanism for applying a drag force to said spool by braking rotation of said spool in a direction reeling off the fishing line, said drag mechanism having
• a drag knob screwed to a front end of said spool shaft, said drag knob including a main knob unit and a presser unit that is pressed down by said main knob unit, at least a portion of said presser unit being accommodated in said main knob unit, and
• at least one drag disk that is pressed together by said drag knob, said disk being accommodated in said spool,
• at least one of said spool and said main knob unit having
• a body extending along an axis and having first and second end faces at opposite ends of the axis,
• a cylindrical concave portion formed on said first end face,
• a plurality of interlocking grooves that is formed on an inner surface of said cylindrical concave portion and opens to said second face, said plurality of interlocking grooves extending in a direction of the axis of said body up to a groove end which is formed on an axial opposite side of said first end face, said plurality of interlocking grooves being formed at a certain spacing in a circumferential direction, and
• a retaining member inserted into said concave portion from a first-end-face side, said retaining member having
• a plurality of engagement portions that can interlock with said plurality of interlocking grooves, and
• a plurality of contact portions that is formed in one piece with said plurality of engagement portions.