Abstract: A washer based nut has a nut body (11), a frustum disc spring (12) of a countersunk shape and rotatably fitting on the nut body, and a washer (14) for bearing against wooden articles. The washer has a central bore (16) and a round recess (17) formed around the bore and in a top face of the washer, and the round recess (17) formed coaxial with the central bore has a diameter substantially equal to an outer diameter of the frustum disc spring (12) such that the latter is fitted in the round recess. Two or more portions of a circular periphery of the round recess (17) are deformed to retain the washer (14) on the frustum disc spring (12), so that the fastening works are rendered more efficient and manufacture cost of the nuts is reduced, under an easier management of the parts.