Abstract: A screw equipped with locking means, includes a female thread made of a synthetic resin and a male thread made of a metal, or a female thread made of a synthetic resin and a male thread made of a synthetic resin, fitted with each other, the female thread having a double cylindrical boss portion formed at the center thereof so that the male thread may be fitted into the innerside boss portion and the thread portion of the boss may be deformed more or less when pressed against the shaft of the male thread in the direction perpendicular thereto through the resilience of the synthetic resin, which is the material of the female thread, by pressing the terminal end of the innerside boss portion against the flange portion of the male thread or a member to be fixed at the final stage of clamping the screw. A female threaded nut may have a blind bore with a projection at the bottom for engagement and deformation by a cutter on the end of a bolt.

Abstract: A spool for a reversible-type correction tape assembly comprising a cap and a spool shaft and improved releasable fastening means therebetween. The spool shaft is adapted to receive a correction ribbon-winding core axially-slideable, but not rotatable around the axis thereof. The spool shaft comprises a sleeve having a top cap-receiving section which has an outer cap-engaging surface which receives a cap detachably mounted thereon so that the winding core does not slip off of the spool shaft. The cap has a depending wall having an inner shaft-engaging surface for engaging the cap-engaging surface of the spool shaft. The engaging surface of the cap or of the spool shaft is provided with a projection extending in a radial direction, and the other engaging surface is provided with a recess or hole capable of receiving the projection.