Abstract: The invention relates to a coupling tube for a screwdriver head having a main body, a socket, a spring element and two engaging rings. One end of the main body is formed with an engaging seat for fixing a screwdriver's head therein by use of an engaging element. The engaging element made of steel bar is bent in the shape of a semicircular ring. The main body has an external annular slot for receiving the engaging element. The middle part of the annular slot is opened for communicating with the engaging seat of the main body. Accordingly, the prearranged engaging face of the engaging element can project into the engaging seat for improving the stability when the screwdriver's head is inserted into the engaging seat.

Abstract: The invention relates to a coupling tube for a screwdriver head having a main body, a socket, a spring element and two engaging rings. One end of the main body is formed with an engaging seat for fixing a screwdriver's head therein by use of an engaging element. The engaging element made of steel bar is bent in the shape of a semicircular ring. The main body has an external annular slot for receiving the engaging element. The middle part of the annular slot is opened for communicating with the engaging seat of the main body. Accordingly, the prearranged engaging face of the engaging element can project into the engaging seat for improving the stability when the screwdriver's head is inserted into the engaging seat.

Abstract: The present invention relates to a magnetic connecting tube for a screwdriver head with a main body, a push element, a spring element, a fastening ring, a block member and an engaging element. The main body having an engaging hole at one end thereof for receiving a hexagonal head which is secured by the engaging element in position. The main body includes under the engaging hole a through hole in which two permanent magnets are so arranged that the repulsive poles face to each other. When the hexagonal head is inserted into the engaging hole, it presses against the upper permanent magnet. In order to drive out the hexagonal head by means of the effect of the push element and the engaging element, the repulsive force between the permanent magnets is utilized to repel the hexagonal head out of the engaging hole. Meanwhile, the upper permanent magnet has the magnetic force to attract the hexagonal head such that the hexagonal head can be firmly attached and can't fall out of the engaging hole.